NHS Choices

Does 'ginger gene' offer key to younger looking skin?

NHS Choices - Behind the Headlines - Fri, 29/04/2016 - 14:30

"'Secret' of youthful looks in ginger gene," BBC News reports. Dutch researchers have found evidence that a gene associated with red hair – the MC1R gene – may also have an impact on how young or old a person looks for their age.

This study examined the facial appearance and genetics of thousands of Dutch elderly adults. The researchers found four DNA sequence variants in the MC1R gene were linked to perceived facial age. These variants were already known to be associated with red hair, pale skin and sun spots.

People who carried two copies of these variants looked almost two years older than people who didn't carry any. Those who carried a single copy looked about one year older.

The researchers hope their findings may spark new leads into understanding the biological basis of youthful looks, and maybe even lead to new anti-ageing treatments.

However, this is some way off. There are likely to be various other genetic factors associated with ageing.

Of course, our genetics don't provide the whole answer to youth and vitality. Our lifestyle and environment – such as whether we drink or smoke and how much UV exposure we get – have a massive influence.

All of these factors can cause premature ageing of the skin. Conversely, a good diet and regular exercise can help boost the appearance of your skin.

We can't change our genetics, but we can change our lifestyle to give us the best chance of a healthy and happy life.

Read more about how to look after your skin

Where did the story come from?

The study was carried out by researchers from the Beijing Institute of Genomics in China, Erasmus MC University Medical Center and Leiden University Medical Center in the Netherlands, and the University of Leeds.

Funding was provided by the Erasmus University Medical Center Rotterdam, Unilever, and the Netherlands Genomics Initiative and the Netherlands Organization of Scientific Research.

The study was published in the peer-reviewed journal Current Biology on an open access basis, so it is free for you to read online.

Three of the authors work for Unilever. The study says: "Although no products were tested, this work could potentially promote the use of anti-ageing products and lead to financial gain for Unilever."

Some sections of the media got themselves into a right muddle regarding the implications of the research, as several headlines imply that redheads look two years younger. This isn't the finding of this research.

The study examined four variants in the MC1R gene that are known to be associated with red hair, pale skin and sun spots.

It found people who carried two copies of any of these four variants looked two years older. So, if anything, this seems to imply that the "ginger" variants were associated with looking older, not younger.

But it's not as simple as this. The variants were lumped together, so you can't assess the effect of any particular variant combination, therefore muddying any specific links.

The researchers also don't make any explicit links with hair colour or skin colour – and argue age perception was independent of these variables.  

Why the MC1R gene can have an influence on skin appearance therefore remains a mystery.

What kind of research was this?

This genome-wide association study involved a large cohort of Dutch people of European descent. It aimed to identify genes linked to perceptions of facial ageing and wrinkles.

As the researchers say, the desire to look young for your age is a long-standing one, which is likely to be due to its associations with health and fertility.

However, the biological basis of why people look older or younger for their age isn't understood. Understanding this could potentially be a step towards the development of new anti-ageing therapies.

What did the research involve?

The first part of the study involved participants of the Rotterdam study – an ongoing follow-up cohort set up in 1990 that has included 2,693 elderly Dutch Europeans.

Researchers of all ages, mainly British, looked at front and side photos of their faces and guessed their age to fit within five-year age bands.

Facial features such as wrinkles and pigment marks were measured objectively using image analysis software.

The researchers then analysed participants' entire DNA, looking at more than 8 million single letter variants – single nucleotide polymorphisms, or SNPs – in the DNA sequence to identify those that had the strongest link with perceived facial age. 

The researchers then verified their findings in two other cohorts: the Leiden Longevity Study, including 599 Dutch Europeans, and the TwinsUK Study, including 1,173 female Europeans.

What were the basic results?

In the Rotterdam cohort, the researchers identified several DNA variants on the MC1R gene that were significantly associated with perceived age, after adjustment for age, sex and wrinkles.

Four of these MC1R DNA variants were highlighted as markers for further study, given that they have been previously associated with red hair, pale skin and age spots.

Compared with people who did not carry any of these four variants, people who carried a single copy of one of them looked about one year older, while people who carried two copies of any of the ageing variants looked about two years older. The effect of these variants seemed to be greater in men than women.

In the Leiden and Twin studies, they confirmed the association with these four MC1R DNA variants.

The link seemed to be consistent regardless of sun exposure and skin colour, but was weaker for darker skin tones.   

How did the researchers interpret the results?

The researchers concluded that, "A role for MC1R in youthful looks independent of its known melanin [pigment] synthesis function is suggested.

"Our study uncovers the first genetic evidence explaining why some people look older for their age and provides new leads for further investigating the biological basis of how old or young people look."

Conclusion

As the researchers rightly say, the quest for prolonged youth and vitality is a longstanding one. This study uncovers another possible genetic reason why some people of the same age may look slightly older or younger than each other. 

The researchers hope their findings may spark new leads into understanding the biological basis of youthful looks, and maybe even one day lead to new anti-ageing treatments.

The findings will undoubtedly provide a valuable contribution to the science of ageing, but we shouldn't assume that DNA sequence variants in the MC1R gene give the whole answer.

There are likely to be many other unexplored genetic variants that have a link with ageing, maybe with greater or less of an effect than the variants studied here.

Of course, our genetics don't give the whole answer to youth and vitality. Our lifestyle and environment – such as our diet, the amount of exercise we take, whether we drink or smoke, and how much UV exposure we give our skin – have a massive influence.

Another factor to consider is that this study was only looking at perceived ageing on account of how the person's face looked. Looking more youthful may not necessarily correlate with good physical health and fertility.

If new anti-ageing treatments are developed, they will be some way down the line, and one thing we can't change is our genetics.

What we can change, though, is our lifestyle to give us the best chance of a healthy and happy life.

Find out how becoming more active can boost both your mental and physical wellbeing – so even if you don't look younger, you could end up feeling younger.   

Links To The Headlines

'Secret' of youthful looks in ginger gene. BBC News, April 29 2016

Gene linked to youthful looks has been discovered, scientists claim. The Guardian, April 28 2016

Ginger gene helps you to look two years younger. The Daily Telegraph, April 29 2016

Secret to 'eternal youth' found in GINGER gene that makes you look two years younger. Daily Mirror, April 28 2016

Secret of looking younger revealed: Half of us have an 'ageing gene' (and it helps redheads look TWO years younger). Mail Online, April 29 2016

Links To Science

Liu Fm Hamer MA, Deelen, J, et al. The MC1R Gene and Youthful Looks. Current Biology. Published online April 28 2016

Categories: NHS Choices

Short bursts of intense exercise 'as good' as endurance training

NHS Choices - Behind the Headlines - Thu, 28/04/2016 - 14:45

"Researchers have found that short bursts of intense exercise produce similar results to traditional longer-duration workouts," the Mail Online reports.

Researchers compared two types of exercise programme over a 12-week period with a control. The two programmes were:

  • a 10-minute "intense" workout, three times a week (referred to as Sprint Interval Training)
  • a 50-minute moderate intensity workout, once a week

At the end of the study, they found similar improvements in reliable fitness markers in both groups, such as the body's response to insulin, peak uptake of oxygen and the functioning of muscle cells. However, it is uncertain that the changes seen would have an effect on cardiovascular disease risk and outcomes in the long term.

The study was also quite small (just 25 young men), and the results ideally need verifying in a larger trial, including a study of wider population groups, such as women and different age groups. The study showed no effect on the men's weight or body mass index (BMI), and did not include information about any adverse effects or risks.

The message that your health may benefit from a 10-minute workout is welcome for anyone who struggles to find time to exercise. However, the researchers warn that very high-intensity exercise is not suitable for everyone.

There are also questions over its safety. Famously, in 2013, the broadcaster and journalist Andrew Marr blamed high-intensity training for triggering his stroke.

If you think you are very unfit, it is probably best to build up your fitness gradually, rather than trying to go all-out straight away.

 

Where did the story come from?

The study was carried out by researchers from McMaster University in Canada and was funded by the Natural Sciences and Engineering Research Council and McMaster University.

The study was published in the peer-reviewed journal Public Library of Science (PLOS) One on an open access basis, so it is free to read online.

The Mail Online's headline that you only need a "minute of exercise" is a bit disingenuous, as the intervals of high-intensity exercise were within a 10-minute session, which included a warm-up and warm-down, and was done three times a week. However, the full text of the story quickly makes that clear, and reports the study reasonably accurately.

 

What kind of research was this?

This was a randomised controlled trial (RCT), which is a good way of finding out if a treatment works. Researchers wanted to know whether very short, high-intensity exercise could improve health measures as much as moderate-intensity exercise, when compared to a group who did a "no exercise" programme.

 

What did the research involve?

Researchers recruited 27 men (two later dropped out) who did little exercise and whose average age was 27. They matched them for similar age, BMI and peak oxygen uptake. They were then randomly assigned to either high-intensity sprint interval training (SIT), traditional moderate-intensity continuous training (MICT), or to a control group which was not given an exercise programme.

They carried out a number of tests on their cardiovascular and metabolic health at the start, during, then again after they finished the 12-week programme. They then compared results of the two exercise groups to the control group.

The tests included:

  • peak oxygen uptake (VO2 peak), measured through a mask worn while cycling on an exercise bike – high oxygen uptake shows the heart and lungs are working efficiently
  • insulin sensitivity index (CS1) measured by monitoring how quickly the body clears glucose from the blood, after it's been infused into a blood vessel – poor insulin sensitivity can lead to type 2 diabetes
  • muscle mitochondrial content, measured by taking a muscle biopsy – mitchondiral content gives an indication of how efficient the muscle is at using energy

Both exercise programmes were carried out using exercise bikes and included a two-minute warm-up and three-minute cool-down, cycling at low intensity. For the SIT programme, men cycled three 20-second bursts of "all out" effort, separated by periods of two minutes of low-intensity cycling, adding up to 10 minutes in total. For the MICT programme, they cycled for 45 minutes at approximately 70% of maximal heart rate, adding up to 50 minutes total.

 

What were the basic results?

Both exercise groups improved on the three tests, while the control group did not show much difference on any test.

Maximum oxygen uptake improved by about 19% for both exercise groups. Insulin sensitivity improved by 53% for men in the SIT programme and 34% for men in the MICT programme, while the measure of mitochondrial content in muscle cells rose 48% after the SIT programme and 27% after MICT.

None of the men showed much change in their weight or BMI, although body fat percentage decreased for men on either exercise programme.

 

How did the researchers interpret the results?

The researchers said their study showed that a weekly exercise programme of 30 minutes, including three minutes of intense intermittent exercise, was as effective as 150 minutes a week of moderate-intensity, continuous training on three measures of cardiovascular and metabolic health.

"Considering that a large number of individuals do not meet the current physical activity recommendations, there is value in exploring the potential benefits of exercise strategies that involve reduced time commitment," they say. However, they warn that, "this type of exercise requires a very high level of motivation and is clearly not suited for everyone."

 

Conclusion

The idea that a 10-minute workout could have the same benefits as spending 45 minutes in the gym is tempting. The researchers found it may improve specific markers of health, in one group of young men.

However, this is a small study in a specific population, and we don't know whether it would have comparable effects in older people or women. Also, we don't know the long-term effects of this type of training programme on people's health.

Studies that look at the effects of an intervention, whether it's exercise, diet or medicine, on health measures such as insulin resistance and oxygen uptake, can only give us a short-term, partial picture. What we really want to know is whether an intervention will reduce your chances of having a heart attack or stroke, or of getting diabetes, or dying earlier. Unfortunately, that information can only come from very long-term studies, which are expensive.

One gap in the study is assessment of safety or negative effects of this type of exercise. High-intensity exercise has been linked in the media to the risk of stroke, especially after broadcaster Andrew Marr suffered a stroke shortly after completing an intense session of exercise.

This study doesn't report any adverse effects, nor does it address safety issues. It is probably too small and of too short a duration to be able to detect any. Ideally, some comparison of the risks of strokes or heart attacks with different types of exercise would be needed. However, this would require a large trial and with long enough duration to identify differences. 

There's no doubt that most of us need to do more exercise than we do, and that exercise has many health benefits. If you're concerned about the safety of a new exercise programme, it's best to talk to your doctor. You might need to start slowly and build up the amount and intensity of exercise you do, especially if you already have a medical condition. 

Government guidelines recommend that adults in the UK should do at least 150 minutes a week of moderate-intensity exercise, or 75 minutes of vigorous exercise, as well as exercise to strengthen muscles. Read more about health and fitness.

Links To The Headlines

Is a MINUTE of exercise all you need? Researchers find 60 seconds of hard work in the gym can be as beneficial as a 45 minute endurance session. Mail Online, April 28 2016

Links To Science

Gillen JA, Martin BJ, MacInnis MJ, et al. Twelve Weeks of Sprint Interval Training Improves Indices of Cardiometabolic Health Similar to Traditional Endurance Training despite a Five-Fold Lower Exercise Volume and Time Commitment. PLOS One. Published online April 26 2016

Categories: NHS Choices

Yoga 'probably good for asthma symptoms and quality of life'

NHS Choices - Behind the Headlines - Thu, 28/04/2016 - 13:05

"Yoga could help asthma sufferers, research finds," reports The Independent.

A major review of existing data found there is "moderate-quality evidence" that yoga improves both symptoms and reported quality of life in people with asthma.

Yoga is an ancient form of exercise that focuses on strength, flexibility and breathing to boost physical and mental wellbeing.

Hong Kong-based researchers reviewed previously published data to see if yoga could improve symptoms and quality of life for people with asthma, compared with usual care or a dummy therapy.

Data from 1,048 people who took part in 15 randomised controlled trials (RCTs) was analysed. The researchers found small improvements for quality of life and symptoms, and a reduction in asthma medication use. However, the only meaningful clinical difference was for quality of life.

The review was well designed, but reviews are only as good as the studies they include – there was a high risk of bias in many studies.

There is also no comparison with other forms of exercise that could be equally effective in improving quality of life for people with asthma.

Still, one of the positives of yoga is that, provided you train with a properly qualified instructor, it is relatively risk-free and does not usually have any side effects or complications.

Read more advice about getting started with yoga

Where did the story come from?

The study was carried out by researchers from the Cochrane Collaboration and was funded by the National Institute for Health Research. 

It was published online via the Cochrane Library in the peer-reviewed Cochrane Databases of Systematic Reviews. The Cochrane Library is a non-profit organisation, so, like all their research, the review is open access and can be read for free online.

This story has been reported relatively accurately in the UK media, with a clear message that the findings are not entirely reliable because of the inclusion of flawed studies. We also don't know whether yoga has any negative effects, if any.

However, the Daily Mail's headline that yoga could help people with asthma "get their breath back" and reduce the risk of asthma attacks is rather misleading – this is not what this review concluded.

There was also some inaccuracy with The Independent's story, which incorrectly stated that participants were aged between six months and 23 years old – this was actually how long people had asthma for. We're not sure how you could get a six-month-old baby to start learning yoga.  

What kind of research was this?

This systematic review aimed to assess the effect of yoga in people with asthma.

A review like this combines data from individual studies to form conclusions about the current state of the evidence on the effectiveness and safety of an intervention.

Caution should always be taken with the results, however, as a systematic review is only as reliable as the studies included in the analysis. 

What did the research involve?

A comprehensive search of medical databases, trial registries, and hand-searching of relevant journals and meeting abstracts was carried out to identify studies for inclusion in the review.

The researchers decided to only include RCTs that compared yoga with usual care, no intervention, or a dummy intervention – a "sham" treatment.

They measured the following outcomes:

  • quality of life
  • asthma symptom score
  • asthma control
  • lung function measures
  • asthma medication usage
  • adverse events

After relevant studies were chosen, data was extracted on the characteristics of participants, interventions, methodology, and outcomes. Outcome data was combined where appropriate and analysed using statistical methods.  

What were the basic results?

Fifteen trials were included in the study, with a total of 1,048 participants. Participants mostly had mild to moderate asthma for a range of 6 months to more than 23 years.

The quality of the studies included was assessed as ranging from very low to moderate.

Analysis found some evidence that yoga may improve outcomes in people with asthma compared with usual care or a dummy intervention:

  • quality of life – mean score difference on the seven-point scale of the Asthma Quality of Life Questionnaire (AQLQ) 0.57 units (95% confidence interval [CI] 0.37 to 0.77); 0.5 units is considered clinically meaningful
  • improve symptoms – standardised mean difference 0.37, 95% CI 0.09 to 0.65; this is equivalent to a small effect
  • reduce medication usage – relative risk 5.35, 95% CI 1.29 to 22.11; the wide range of this confidence interval casts the reliability of the result into doubt

To put these findings into context, the change in quality of life had a minimal clinically important difference, while yoga had no clinical benefit for symptoms.

Yoga did not improve lung function during the course of the study and there were no serious side effects associated with the practice, but there was limited data on this outcome.  

How did the researchers interpret the results?

The researchers concluded that, "We found moderate-quality evidence that yoga probably leads to small improvements in quality of life and symptoms in people with asthma.

"There is more uncertainty about potential adverse effects of yoga and its impact on lung function and medication usage.

"RCTs with a large sample size and high methodological and reporting quality are needed to confirm the effects of yoga for asthma."

Conclusion

This well-conducted systematic review aimed to assess whether yoga could improve outcomes for people with asthma when compared with usual care or dummy therapy.

Using statistical methods, small improvements were found for quality of life, symptoms, and a reduction in medication use.

However, the only effect that could make a meaningful difference for someone is the small benefit seen for quality of life.

The review itself was well designed. Efforts were made by the researchers to avoid combining studies that differed significantly in their design and methods.

However, this study did have some limitations:

  • The studies included were of very low to moderate quality, and many were small in sample size, which has an impact on the reliability of the findings.
  • The studies varied widely in their described yoga interventions and additional drug therapy.
  • Some of the analyses included small numbers of participants and the confidence intervals were therefore wide, which reduces the reliability of the estimate.
  • Data on some outcomes, such as unwanted side effects, was limited.
  • Most of the studies included those with mild to moderate asthma, so yoga may not relieve symptoms in those that need it the most.

This review does not produce conclusive evidence that yoga would be beneficial to people with asthma, and any negative effects were not investigated.

The main thing it found was that yoga may improve quality of life – however, this could be the case if you take part in many types of physical activity, not just yoga. There was no comparison with other forms of exercise.

If you have asthma, there is usually no reason why you should have a restricted life. There are several things you can do to keep asthma under control:

  • make sure to take all medicine as prescribed
  • attend regular reviews
  • understand your symptoms – know when to take your inhaler or call for emergency help
  • keep away from known triggers, such as animal fur and cigarette smoke

Read more lifestyle advice about how to live better with asthma.

Links To The Headlines

Yoga could help asthma sufferers, research finds. The Independent, April 27 2016

Can yoga really help to fight asthma? Daily Mirror, April 27 2016

Yoga could help asthma sufferers get their breath back: Exercises found to decrease chance of attacks by relaxing muscles in the airways and anxiety that can cause them. Daily Mail, April 27 2016

Links To Science

Yang Z, Zhong H, Mao C, et al. Yoga for asthma. Cochrane Database of Systematic Reviews. Published online April 27 2016

Categories: NHS Choices

Vitamin D, fish oil and folates may enhance antidepressants

NHS Choices - Behind the Headlines - Wed, 27/04/2016 - 14:30

"Do antidepressants work better when taken with supplements?," the Mail Online asks.

A new review of existing evidence suggests that, "Omega-3 fish oils, certain amino acids, folate and vitamin D" may boost the beneficial effect of antidepressants, the Mail says.

There was also tentative evidence that S-Adenosyl methionine (SAMe) – a type of amino acid supplement popular in some countries – may boost the effects of antidepressants.

Researchers from Melbourne, Australia, reviewed the evidence about combining antidepressant treatment for depression with "nutraceuticals" – nutrient-based supplements produced to pharmaceutical standards. This means that consumers can be confident about information relating to important issues such as dosage and ingredients. 

The researchers looked at 40 studies, of varying quality, to pool the results where possible and draw conclusions. They found that omega-3 supplements (usually derived from fish oil) had a significant effect, but there were varying results for other nutraceuticals studied.

In some cases, only one or two small studies had been published, making it hard to rely on the results. The researchers also found evidence that more positive studies than expected had been published, suggesting that some negative studies had not been published (publication bias).

The researchers say they have shown that EPA-rich omega-3 oil "may be recommended" as an additional treatment for depression, alongside antidepressants. But they caution that people taking antidepressants should talk to their doctors before starting any supplements.  

 

Where did the story come from?

The study was carried out by researchers from the University of Melbourne, Swinburne University of Technology, Deakin University, the National Centre of Excellence in Youth Mental Health, and the Florey Institute for Neuroscience and Mental Health, all in Australia, and Harvard Medical School in the US. Information on funding was not provided in the study. 

The study was published in the peer-reviewed journal The American Journal of Psychiatry. Six of the seven authors reported financial interests in the field, mainly research funding and payments for speaking and writing about pharmaceuticals and nutraceuticals.

The Mail Online reported the results of the study uncritically, without considering the strength of the evidence for the different nutrients studied. Of the three nutrients named in its headline, the study only found strong evidence for omega-3.

 

What kind of research was this?

This study was a systematic review, with meta-analyses performed where there was sufficient evidence to do so. The researchers found enough studies to perform meta-analyses for just two nutrients: omega-3 and folic acid.

Meta-analyses are a good way of pooling results of studies, giving an overall view of whether a treatment works. However, systematic reviews and meta-analyses are only as good as the individual trials that go into them.

 

What did the research involve?

Researchers searched for any studies in English that looked at the effects of adding one of 14 nutrients known to be involved in nerve cell function to antidepressant treatments. They divided them into groups and summarised the results. For nutrients where they had at least two randomised controlled trials (RCTs), they carried out a meta-analysis.

They included open-label studies (where people knew which treatment they were taking) and uncontrolled studies, where they looked at the effect of adding a nutraceutical treatment to an antidepressant for people who had not responded to an antidepressant, without using a placebo for comparison. People in the studies had to have been diagnosed with a major depressive disorder or have ongoing depression.

For most of the nutrients, they summarised the results from the different studies, stating how many showed a positive effect and how many did not. For folic acid and omega-3 oils, they carried out meta-analyses of the mean difference between treatment and placebo, in the change from start to end of the study.

 

What were the basic results?

The most reliable evidence came from the meta-analyses:

Omega-3

Eight studies, all RCTs containing 20 to 122 people, looked at the effect of omega-3. Six of the eight studies showed a statistically significant reduction in depression scores for the treatment group, compared to the placebo group. The meta-analysis showed a statistically significant effect size of 0.61 for the difference between the treatment and placebo group (p=0.0009). It is not possible to interpret how clinically important this effect size is, as there was no information about the actual depression scores in the studies.

Folic acid

Four RCTs looked at the effects of folic acid. Two of them showed a reduction in depression scores for people taking folic acid, but one big study showed no significant effect. The meta-analysis showed no statistically significant effect size.

Other nutrients

Other nutrients which the researchers said showed positive effects included:

  • an amino acid based nutrient called S-adenosylmethionine (SAMe) – three small open-label studies found a positive effect; however, the only RCT found no significant effect
  • methylfolate, a type of folate – three small trials (one open-label) found a positive effect; one larger RCT found no significant effect
  • vitamin D – one RCT and one open-label study, both fairly small, found a positive effect

The other nutrients studied either had only one study looking at them, or mixed results. Evaluation of the meta-analyses showed big differences between the study results, and potential publication bias (where studies are published if they are positive, but not if they are negative).

 

How did the researchers interpret the results?

The researchers were upbeat about the results, especially for omega-3 oils, which they said could now be recommended for use as an add-on treatment alongside antidepressants, on the basis of their results.

They conclude: "several nutraceuticals may hold a potential clinical application to enhance the antidepressant effect of medications" and that groups issuing guidelines for doctors should consider including nutraceuticals.

However, they admit that good-quality, large RCTs are now needed.

 

Conclusion

Many people with depression benefit from taking antidepressants, but some either don't find them helpful, or don't completely recover while taking them. A safe and effective way to boost the effects of antidepressants would therefore be useful.

This study is a useful summary of which nutrients have been tested as an add-on to antidepressants, and an overall indication of what the studies found. It shows that, for most of these nutrients, the evidence comes from small studies of varying quality and length, and that we need bigger, better studies to get a true picture of their effects.

For the nutrients where there was sufficient evidence to carry out a meta-analysis, the difficulty is that the way the results are presented makes it hard to tell how much of an effect the nutrients actually had on people's depression.

We don't know whether the difference in the effect of treatment seen with omega-3 supplements amounted to more people getting completely better from depression, or whether some people's depression scores on questionnaires improved a few points, but not enough to make much difference to their quality of life. The researchers describe the effect as "moderate to strong".

If you are taking antidepressants and feel they are not making much difference, talk to your doctor. Antidepressants take a while to start working properly, so you may need to wait a little longer. If you've been taking them for a while and they don't help, talk to your GP about trying another type of antidepressant, or a different dose. If you are interested in taking a supplement alongside your antidepressant, talk to your doctor first.

Finally, it's important to remember that the study was looking at "nutraceuticals" – nutrient-based supplements produced to pharmaceutical standards. If you do decide to try a supplement, make sure it is from a trusted source with a reputation for safety and high quality.

Links To The Headlines

Do antidepressants work better when taken with supplements? Fish oils, folate and vitamin D found to 'significantly improve mood'. Mail Online, April 26 2016

Links To Science

Sarris J, Murphy J, Mischoulon D, et al. Adjunctive Nutraceuticals for Depression: A Systematic Review and Meta-Analyses. The American Journal of Psychiatry. Published online April 26 2016

Categories: NHS Choices

Bedbugs 'prefer certain colours'

NHS Choices - Behind the Headlines - Tue, 26/04/2016 - 15:28

"Bed bugs appear to have a strong preference for particular colours," BBC News reports. A new study suggests the pests prefer red and black and "hate yellow and green".

It's unclear whether changing the colour of your bed sheets would prevent an infestation of bedbugs, though certain colours could prove useful for traps.

Bedbugs can be upsetting and cause a rash or itchy bumps on your skin. They don't pass on infectious diseases, but can cause an allergic reaction in some people, such as severe itching.

They can be present in even the cleanest of homes, but are more common in crowded lodgings and places with a high turnover of occupants.

Some tell-tale signs to look out for are blood spots on your sheets. Checking in the crevices of your mattress is a good way to spot them.

In this study, researchers used coloured tents in a petri dish and gave the bedbugs 10 minutes to choose their dwelling. Overall, bedbugs strongly preferred red and black, but tended to avoid colours such as green and yellow.

When they were split into sub-groups, the bedbugs' preferences varied by gender, whether they had recently been fed, and life stage.

However, this research can't tell us that yellow or green sheets would prevent an infestation of bedbugs.

If you do suspect bedbugs, it's recommended that you contact your local pest control firm, making sure they are a member of the British Pest Control Association, or your local council. 

Where did the story come from?

The study was carried out by researchers from Union College in Lincoln and the University of Florida.

Funding was provided by the Florida Pest Management Association and a University of Florida Endowed Professor Fund. Florida Pest Management Association is the trade group for the state's pest control companies.

The study was published in the peer-reviewed Journal of Medical Entomology on an open access basis, so you can read it for free online.

While the reporting of the study by the UK media is generally accurate, some of the coverage is not representative of the facts.

Neither the BBC's claim that bedbugs "hate yellow and green" nor the Mail Online's advice that you should "buy yellow sheets and avoid red carpets" is supported by the evidence.

The Daily Telegraph wins the shameless clickbait award of the day for managing to shoehorn in four Fifty Shades of Grey references in its first two paragraphs.

Some of the media sources carry some interesting speculation from a number of the study's authors.

One of the co-authors, Dr Corraine McNeill, explained: "We originally thought the bedbugs might prefer red because blood is red and that's what they feed on."

Dr McNeill went on to suggest that, "The main reason we think they preferred red colours is because bedbug themselves appear red, so they go to these harbourages because they want to be with other bedbugs.

"The bugs appeared to dislike yellow and green shelters, possibly because these bright colours remind them of brightly lit areas that are less safe to hide in." 

What kind of research was this?

This experimental laboratory study aimed to find out if bedbugs have a preference for living in specific-coloured dwellings.

This study is able to identify themes by observing the bedbugs' movements and examining differences by gender, life stage and nutritional status.

However, it cannot prove why they made their choices or if they would do so outside of the laboratory environment.  

What did the research involve?

The researchers set up an experiment that used small tents made from different coloured card in a petri dish to test where bedbugs would prefer to dwell.

Tests were performed to see if there were differences resulting from gender or nutritional status – starved (not fed within a week) or fed (blood one to two days before).

In a two-colour test, the bedbugs were to choose between the following eight colour dwellings against the standard white tent:

  • lilac
  • violet
  • blue
  • green
  • yellow
  • orange
  • red
  • black

A single bedbug was placed in the middle of the petri dish arena and was given 10 minutes, after which time the colour of the dwelling the bedbug was found under was recorded.

The next experiment used seven coloured tents – as above, excluding yellow – in a semi-circular arrangement and the same test was performed.

Bedbugs were tested either individually or aggregated in groups of 10 at a time. Groups were either all males, all females, or a 1:1 ratio of males and females.

Researchers also used these seven colours to test whether female bedbugs prefer to lay their eggs in dwellings of specific colours. 

What were the basic results?

Researchers found the two-choice and seven-choice colour tests indicate that red (28.5%) and black (23.4%) dwellings were the prime choices for bedbugs, while yellow and green were not popular at all. The colours chosen changed according to gender, nutritional status, aggregation and life stage.

Female bedbugs preferred lilac and violet, compared with males, who preferred red and black. When the bedbugs were fed, they appeared to be drawn to the orange and violet dwellings.

Significantly more eggs were laid in red, blue, orange and black dwellings compared with green. Bedbugs at different stages of life also appear to show different colour preferences, which may be down to the development of their eyes.  

How did the researchers interpret the results?

The researchers concluded that, "This study has given further support for bedbug preferences that may indicate that a mechanism exists for colour discrimination in bedbugs.

"Our findings should be useful in bedbug trap design as an attempt to enhance trap captures." 

Conclusion

This experimental laboratory study of bedbugs aimed to see whether the pests showed a colour preference for their dwellings.

The study found, overall, bedbugs strongly preferred red and black, but tended to avoid colours such as green and yellow.

When split into sub-groups, preferences varied by gender, whether they had recently been fed, and their life stage.

It is not clear why the researchers did not test yellow in their seven-colour test, as it would have been interesting to see whether the two-colour findings were replicated.

While these findings are of some interest and have been widely covered in the media, even the researchers say we shouldn't rush out to buy yellow sheets.

The research was only conducted over a timescale of 10 minutes, so we do not know what would have happened over time – for example, whether bedbugs would be less likely to mate and produce viable eggs if they were only given a yellow environment, or conversely whether their numbers would greatly increase in a red or black environment.

What we do know is that they need human blood to survive, prefer places that are warm, and can be carried on clothing and linen, hence why they are more common in hostels and places with a high turnover of people.

Bedbugs are very difficult to spot and can squeeze into the smallest of spaces. They are not attracted to dirt, so are not an indication of an unclean home.

Signs to look out for include:

  • an unexplained rash on the skin, or itchy bumps
  • black spots of their dried faeces on your mattress
  • mottled shells, which they may have shed
  • blood spots on your sheets where they may have been squashed
  • looking in the crevices of your mattress to see if you can spot them
  • in some cases of a large infestation, there could be a unpleasant, musty scent in rooms

If you do suspect bed bugs, it's recommended that you contact your local pest control firm, making sure they are a member of the British Pest Control Association, or your local council.

To prevent a bedbug infestation, inspect your mattress regularly for common signs and take immediate action if necessary. Avoid buying second-hand mattresses and be wary of old beds you might be using in rented accommodation.

Keeping your bedroom tidy and removing clutter, especially from the floor and under your bed, reduces the amount of hiding places for bedbugs.

Links To The Headlines

Bed bugs repulsed by certain colours. BBC News, April 25 2016

Bedbugs won't suck your blood - but you'll have to buy very specific sheets. Daily Mirror, April 26 2016

How to get rid of bed bugs? Buy yellow sheets and avoid red carpets: Pests have favourite colours when searching for shelter. Mail Online, April 25 2016

Why Christian Grey’s ‘red room’ is more likely to have bed bugs. The Daily Telegraph, April 25 2016

Links To Science

McNeill CA, Pereira RM, Koehler PG, et al. Behavioral Responses of Nymph and Adult Cimex lectularius (Hemiptera: Cimicidae) to Colored Harborages. Journal of Medical Entomology. Published online April 25 2016

Categories: NHS Choices

Med diet best for heart disease (but some junk food won’t hurt)

NHS Choices - Behind the Headlines - Mon, 25/04/2016 - 11:28

"People with heart disease have a lower risk of heart attack and strokes if they eat a Mediterranean-style diet," The Guardian reports.

The study it reports on also suggests that the occasional Western-style treat probably doesn't pose much of a risk for people with heart disease.

After recruiting more than 15,000 people with heart disease from 39 countries, researchers scored their diets for Mediterranean elements such as eating plenty of whole grains, fruits, vegetables, legumes, fish, some alcohol, and some meat. They also scored diets for Western diet elements, such as consumption of refined grains, sweets and desserts, sugared drinks, and deep-fried foods.

After an average of 3.7 years, death, non-fatal heart attack or stroke occurred in 7.3% of people with a Mediterranean score of 15 or more – about 3% less than those scoring 14 or below (around 10%).

Surprisingly for some, higher Western diet scores did not increase the risk of these same problems.

The findings related to a very specific group: adults with stable coronary heart disease (CHD) who were at high risk of having a major cardiovascular event. This means the 3% reduction is not generalisable to the wider population, or even to all people with heart disease.

Although heart disease cannot be cured, treatment and lifestyle changes can help manage the symptoms and reduce the risk of further complications.

Some of the reporting promotes the line that "eating good food is more important than avoiding bad food".  

Where did the story come from?

The study was carried out by researchers from universities in the US, New Zealand, Sweden, France, Denmark and Canada, and was funded by pharmaceutical manufacturer GlaxoSmithKline.

The authors involved in the study have financial links with various large pharmaceutical companies or are employed by them.

The study was published in the peer-reviewed European Heart Journal on an open-access basis, so you can read the study online for free.

The media reporting was generally accurate, with many focusing on the finding that the Western diet did not increase major risk of cardiovascular events. Only the Guardian acknowledged that the study also pointed to the benefits of the Mediterranean-style diet.

 

What kind of research was this?

This was a longitudinal study looking at the effect of diet on serious cardiovascular outcomes in adults with CHD.

CHD is the leading cause of death both in the UK and worldwide. It's responsible for more than 73,000 deaths in the UK each year. About 1 in 6 men and 1 in 10 women die from CHD.

 

What did the research involve?

The study analysed data from adults with stable CHD and a high risk of a major cardiovascular event already recruited to a study, called the STABILITY trial. This was designed to test whether a new drug called Darapladib (not currently licensed in the UK) would prevent major cardiovascular events in this high-risk group. Some of the group were taking Darapladib, while others were taking a placebo.

From the STABILITY trial, the researchers used self-reported lifestyle data from 15,482 people from 39 countries to score each for "Mediterranean diet" elements, like eating plenty of whole grains, fruits, vegetables, legumes, fish, alcohol and some meat. They then scored them for "Western diet" elements, such as consumption of refined grains, sweets and desserts, sugared drinks, and deep-fried foods. People were asked to recall both the type and frequency of food during "a typical week".

They then compared the numbers of major cardiovascular events – defined as death, non-fatal heart attack or non-fatal stroke – over the next three years (median 3.7 years) in those with greater Mediterranean or Western diet scores, to see if they were protective or harmful.

The analysis took account of many confounding factors known to affect risk of major cardiovascular events, including:

  • age
  • sex
  • treatment with Darapladib or placebo
  • smoking history
  • CHD severity
  • cardiovascular disease risk factors (diabetes, HDL-cholesterol, history of high blood pressure)
  • LDL – "bad" – cholesterol
  • body mass index (BMI)
  • self-reported physical activity
  • geographic region
  • level of education

The Mediterranean and Western diet scores were totalled and categories defined. For example, most people (56%) scored 12 or less for Mediterranean score, a quarter scored 13 to 14 (26%) and a minority scored 15 or over (18%). Despite the differences in Mediterranean score, Western diet scores were around 12 across all three groups.

 

What were the basic results?

Those scoring highest for a Mediterranean-style had fewer deaths, non-fatal heart attack or non-fatal stroke over an average of 3.7 years. These events occurred in 7.3% of people with a Mediterranean score of 15 or more – about 3% less than those scoring 13 to 14 (10.5%), or less than 12 (10.8%).

For Mediterranean diet scores less than 12, there was no link between increase in score and fewer major cardiovascular events.

But for every point increase on the Mediterranean style diet score over 12, the risk of death, non-fatal heart attack or stroke lowered by 5% (hazard ratio [HR] 0.95, 95% confidence interval [CI] 0.92 to 0.99).

There was no corresponding link between higher Western diet scores and deaths, non-fatal heart attack or strokes over the same period, which was not what the researchers had expected.

 

How did the researchers interpret the results?

The researchers' conclusion was refreshingly simple: "Greater consumption of healthy foods may be more important for secondary prevention of coronary artery disease than avoidance of less healthy foods typical of Western diets."

They also point out the diet is not specific to Mediterranean countries, and is similar to the diet already recommended to people to stop high blood pressure, and is recommended in broader national dietary guidelines.

 

Conclusion

This study showed 3% fewer people with CHD, at high risk of major cardiovascular events, who reported eating the healthiest Mediterranean-style diets, had either died, or had a non-fatal heart attack or stroke over a three-year period than those with less healthy diets. Western diet scores were not related to major cardiovascular events.

The study was large, worldwide and its methods quite robust, all boosting the believability of the findings.

It is possible that unmeasured factors explain all or part of the findings, but the study made a concerted attempt to minimise the chance of this through adjusting for important confounders in their analysis.

Only around 18% of the 15,000 or so studied fell into the Mediterranean-style diet group that showed health benefits; the same link wasn't found in lower-scoring groups. This suggests that most of those studied could potentially benefit from a healthier diet.

It is important to realise that the findings relate to a very specific group: adults with stable CHD who were at high risk of having a major cardiovascular event. The group was even more uncommon than this, as some were also taking an experimental drug called Darapladib as part of a separate study; this reportedly had little impact on the diet-related findings. Therefore, the 3% reduction figure does not apply to the general population, or even to all people with CHD.

That is not to say that a healthy diet won't benefit the wider population – it probably will, but this study didn't look at this or provide a figure of the magnitude of benefit.

What is more applicable to the masses is the clear implication of the study. That a diet high in whole grains, fruits, vegetables, legumes, fish, some alcohol, and lower in meat, has health benefits. This is nothing new and is already incorporated into most healthy lifestyle recommendations and diet advice for people looking to lower their risk of high blood pressure. What the study does add is a quantification of the benefit of a good diet in a specific high-risk group.

Interestingly, higher scores for a Mediterranean diet were more common in the Asia/Pacific and Northern Europe regions than Mediterranean countries themselves. It seems people living in, for example, Japan or Norway are more likely to follow a traditional Mediterranean diet than people living in the Mediterranean.

The finding that a higher Western diet score – usually associated with worse heart health – was not linked to major cardiovascular events was more surprising. These new data suggest, as the study authors put it: "Greater consumption of healthy foods may be more important for secondary prevention of coronary artery disease than avoidance of less healthy foods typical of Western diets."

That shouldn't be taken as a green light to start chugging down the cheeseburgers, especially if you have a history of heart disease. The saying, "the absence of evidence is not the same as evidence of absence" may be clichéd, but like most clichés, it contains an element of truth.

It could be the case that a larger study with a more generalised population could find a link between Western-style diet and increased risk of serious cardiovascular events.

Links To The Headlines

Mediterranean-style diet reduces stroke risk in heart patients – study. The Guardian, April 25 2016

Heart disease patients 'no more likely to suffer a heart attack or stroke if they eat a fatty Western diet after being diagnosed'. Mail Online, April 25 2016

Junk food not harmful to heart when eaten with Mediterranean diet, study finds. The Daily Telegraph, April 25 2016

Links To Science

Stewart RHA, Wallentin L, Benatar J, et al. Dietary patterns and the risk of major adverse cardiovascular events in a global study of high-risk patients with stable coronary heart disease. European Heart Disease. Published online April 24 2016

Categories: NHS Choices

'Transformational managers' may be bad for workplace health

NHS Choices - Behind the Headlines - Fri, 22/04/2016 - 14:30

"Managers who pressurise their staff to go that extra mile risk harming their employees' health," the Daily Mail reports.

New research suggests "transformational managers" – charismatic high achievers – may increase levels of sickness in the workforce.

Supporters of transformational management would say it combines individual charisma and the ability to motivate staff and stimulate employees with being able to gauge the strength and weaknesses of staff members on an individual basis.

A poster boy for transformational management would be the late Steve Jobs of Apple fame.

But playing devil's advocate, you could argue that some managers who try to adopt this style fail to get their approach right, and it's more intimidation than motivation.

Think of the fictional boss from hell, Miranda Priestly, as played by Meryl Streep in the film The Devil Wears Prada. 

Researchers followed Danish postal workers for three years. Those with line managers displaying a transformational leadership style had more sick days off work a year later – about four days more a year. The link was not seen in the subsequent year.

They report some staff members were coming into work even though they were ill – what's known as presenteeism. This could exacerbate health problems and lead to long-term problems with productivity.

So overall, this study shows that transformational leadership may have a dark side, but needs more investigation so we can better understand the link. A longer-term assessment of the effects of presenteeism would also be useful.  

Where did the story come from?

The study was carried out by researchers from the University of East Anglia in the UK and the Danish National Research Centre for the Working Environment. It was funded by the National Work Environment Research Fund.

The study was published in the peer-reviewed journal, Work and Stress.

The media coverage was generally accurate, although the reporting tended to skate over the complexity of the relationship over time and its link with presenteeism.

What kind of research was this?

This longitudinal study followed 155 Danish postal workers over three years to track their presenteeism and sickness levels, and how these work-related measures were impacted by having a line manager with a transformational leadership style.

Transformational leadership was defined as having four main dimensions:

1. idealised influence or charisma – the leader acts as a role model and takes the lead in displaying desirable behaviour

2. inspirational motivation – the leader outlines a clear vision and the way forward

3. intellectual stimulation – the leader encourages employees to make use of their skills and coaches them in making their own decisions

4. individualised consideration – the leader acknowledges individual differences, and adjusts behaviour according to the individual's needs and capabilities

Previous research has shown leaders play a significant role in the sickness absenteeism patterns of their employees, but the question of whether a transformational leadership style increases sick leave has not yet been answered.

The research team thought the added pressure of this leadership style might encourage employees to come to work while unwell, potentially prolonging their own illness and actually increasing the overall number of sick days on a long-term basis. They set out to test this hypothesis.

What did the research involve?

The study interviewed a group of postal workers three times over three years to find out their line managers' leadership style, the number of days they took off work sick, and presenteeism.

To assess sick leave, employees were asked to say how many days they'd taken off work because of personal illness in the last year.

Estimates of presenteeism came from asking employees the question: "In the past 12 months how many workdays have you gone to work even if you were sick?"

Absence and presenteeism levels at year one were used as the reference level, so changes in year two and three were relative to this starting point.

Transformational leadership style was assessed by the employees using the Global Transformational Leadership Scale, a seven-item leadership questionnaire at year one only.

Response rates to the surveys from the postal workers were high in each of the three years, not falling below 86%.

Many eligible people were excluded from the analysis because of missing data on absence or presenteeism, which is a potential problem.

However, the researchers analysed both the included and excluded groups and found them no different in terms of absence or presenteeism rates.

The final sample analysed was 155 workers from 22 teams. The average age was 42 years and most (60%) were men.  

What were the basic results?

The results showed a changing relationship between leadership style and employee sickness over time.

Transformational leadership in year one increased sickness in year two, but not year three.

Postal workers took an average of 11 days off in year one, which increased to 14 in year two (a statistically significant increase) before dropping back to eight days in year three (statistically no different from year one).

The researchers found presenteeism levels in year one modified the link between transformational leadership and sick leave in year three, but not year two. 

A closer look at this relationship in year three found those who reported an average of 14 days more presenteeism in a year than their co-workers were more likely to be negatively influenced by transformational leadership in terms of taking more days off sick.

Groups with less presenteeism were not affected in the same way.  

How did the researchers interpret the results?

The researchers said that, "A large body of literature has found positive relationships between transformational leadership and well-being cross-sectionally (Skakon et al 2010), but it would appear that over time transformational leadership may also have negative effects on employees.

"Our results suggest that transformational leadership behaviours may have an adverse effect on those employees who frequently show up for work while ill.

"The constant pressure from transformational leaders to perform 'above and beyond the call of duty' and the accentuated pressure from the work group may prevent followers from recovering from the pressures at work, and as a result lead to sickness absenteeism."

In terms of solutions, they suggest: "Transformational leadership training should comprise health-related dimensions of transformational leadership.

"For example, intellectual stimulation should focus not only on developing competencies and mastery in followers [employees], but also on building their resilience and coping skills.

"Leaders could also be trained in incorporating wellbeing and health into the vision, goals, and objectives they develop for work groups. As role models, transformational leaders should display healthy behaviours and encourage followers to look after their own health." 

Conclusion

This study shows that a popular leadership style called transformational leadership may increase employee sick days, but this depends on employees' existing tendencies to show up to work when they're ill.

Those who tended to show up to work ill the most were also those most likely to be off sick more when a transformational leader was installed.

The researchers' theory was that those more likely to come into work when they're ill don't have a chance to recover from work and illness fully, leading to more sickness in the long term.

However, this study has a number of limitations to be aware of. Those reporting high levels of presenteeism may have been trying to appear to be good workers who would soldier on and go into work despite being unwell, which could skew the results.

Similarly, postal work – which is somewhat outdoorsy and active – is probably not a good model for most jobs in the UK, many of which are office based. This means the conclusions of this study can't be stretched to apply to all workers and settings. 

Also, sick leave was self-reported by employees, who were asked to recall the number of days they had off because of illness over the past year.

The employees' absence records would have been a more accurate source of days off work, but would not have been restricted to sick leave – also including absence because of a family emergency, for example.

The researchers appeared to have both sets of information available, and said that self-reported sick leave did correlate with employer records of total days off work as you'd expect, although only weakly.

Comparing the effects of leadership between self-reported sick leave and general absence would have given us a better idea of how much this measurement difference affects the end results.

The study was not able to tell us anything about how transformational leadership may exhibit adversely affect health. The hypothesis that this leadership style may prevent employees recovering from illness because of work pressures, leading to more sickness absenteeism, wasn't tested, so remains speculative.

Also, the estimate of transformational leadership style may not have been entirely accurate, as it was based on quite a short questionnaire. Error in this measurement would muddy the link the researchers were trying to assess, and could explain some of the lack of effect found in the short term.

Overall, this study shows that transformational leadership may have a dark side, but needs more investigation to better understand the link.

Some pressure at work can be motivating, but can eventually lead to work-related stress when it becomes excessive. This in turn can lead to symptoms of depression and anxiety.

Whatever the source of your stress, speak to your manager or someone else in your organisation who you feel comfortable talking to.

Read more about coping with workplace stress.

Links To The Headlines

Is your boss making you sick? Managers who pressurise their staff to go that extra mile risk harming their employees' health. Mail Online, April 22 2016

'Inspirational' leadership bad for business. The Daily Telegraph, April 22 2016

Links To Science

Nielsen K, Daniels K. The relationship between transformational leadership and follower sickness absence: the role of presenteeism. Work and Stress: An International Journal of Work, Health and Organisations. Published online April 21 2016

Categories: NHS Choices

Daily low-dose aspirin may help combat cancer

NHS Choices - Behind the Headlines - Fri, 22/04/2016 - 10:00

"Aspirin could help beat cancer: Daily pill can 'cuts odds of dying of breast, bowel and prostate cancer by a fifth'," the Daily Mail reports.

A review of previous studies suggests low-dose aspirin could play a useful role in treating some cancers.

The review looked at 47 studies and attempted to combine the results, looking for evidence of a beneficial effect of low-dose aspirin (which is usually defined as 75-300mg per day) on risk of death in people already diagnosed with cancer.

Significant results were a 24% reduction in risk of death from colon cancer, and possibly an 11% reduced risk of death from prostate cancer. Despite widespread media reports, aspirin was not found to reduce the risk of death from breast cancer.

These results should be viewed with some caution as several studies were omitted from the pooled analyses as they gave conflicting results. In addition, the studies that were included in the analysis  were observational, so they cannot show cause and effect.

This means the overall link may not be so clear cut and more good quality evidence is needed. As the researchers rightly conclude, further, rigorous trials need to be carried out to ensure any benefits of aspirin for people with cancer outweigh the risks.

Where did the story come from?

The study was carried out by researchers from Cardiff University and the University of Cambridge, with no external funding, and was published in the peer-reviewed medical journal PLOS One. This is an open-access journal, so you can read the study for free online.

The study was widely reported by the UK media. The quality of that reporting was decidedly patchy in some quarters.

Several media sources incorrectly reported that aspirin boosts breast cancer survival, which was not found in this study. Also, there wasn't sufficient evidence to say there were "signs that aspirin might work against almost all tumours," as reported by The Times.

The Mail's suggestion that aspirin boosts survival for people with kidney and oesophageal tumours was also inaccurate – the results showed no change in risk of death for these cancers with aspirin use.

The Daily Mirror reports that one of the concerns with aspirin use is the risk of bleeding, but quoted the lead author as saying: "we specifically looked at the available evidence of bleeding and we wrote to all authors asking for further data. In no study was serious or life-threatening bleeding reported." While this is technically true, the Mirror failed to point out that only two trials including 799 people on aspirin had available data on bleeding risk. The authors of 21 trials reported that data on bleeding risk was not recorded and the other authors did not respond to the request for information. 

 

What kind of research was this?

This was a systematic review of studies looking at the effect of aspirin taken by people with a diagnosis of cancer. Some of the studies' results were pooled in a meta-analysis. This systematic review included randomised controlled trials (RCTs) (the gold standard) but also observational studies, which are unable to prove cause and effect.

There was a wide variation in these study types and cancers studied, which is known as heterogeneity. A meta-analysis with a high degree of heterogeneity can lead to inaccurate or misleading results.

 

What did the research involve?

The researchers searched two medical databases, Medline and Embase, for studies of aspirin taken by people with cancer. They identified four RCTs and one review pooling the results of five trials, and 42 observational studies, including large cohort studies.

The studies were grouped according to the type of cancer. Statistical methods were used to work out whether the studies were similar enough to pool or whether they were too different to provide meaningful results.

They also contacted all of the lead authors of the studies requesting data on bleeding risk, as this was only available in two of the published studies.

 

What were the basic results?

In people diagnosed with cancer, aspirin use was associated with a reduced risk of death from colon and possibly prostate cancer, but not breast or any other type of cancer.

Colon cancer

A 24% reduction in risk of death was found from pooling 11 observational studies (hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.66 to 0.88). There were some differences between studies, but they were considered to be similar enough to combine.

However, subset analysis of trials looking at the effect of aspirin for cancers located higher and lower in the colon did not find any difference in risk of death with aspirin. One review of five RCTs found a reduced risk of death from colon cancer, though the researchers were not confident in the reliability of this result. Another small RCT of 57 people did not find that aspirin improved survival.

Prostate cancer

An 11% risk reduction of death from prostate cancer was found with aspirin use after combining the results of eight similar observational studies (HR 0.89, 95%; CI 0.79 to 0.99). There was no risk reduction if all nine of the studies were combined (HR 0.94, 95% CI 0.76 to 1.17).

Breast cancer

Aspirin was found to have no statistically significant effect on breast cancer mortality when combining the results of four similar observational studies (HR 0.87, 95%; CI 0.69 to 1.09).

Other cancers

There was some evidence that aspirin may be effective against cancers with the genetic mutation PIK3CA, but more robust trials were necessary to be confident in the result.

Single observational studies suggested a reduced risk of death for lung, head and neck, and oesophageal cancers plus chronic lymphocytic leukaemia. No difference in risk of death was observed for ovarian, bladder or a mix of female cancers.

 

How did the researchers interpret the results?

The researchers concluded it is, "likely that low-dose aspirin has a beneficial role as an adjunct treatment of cancer". They say the evidence is strongest for colon cancer and for cancers expressing certain genetic mutations.

The researchers also point out the limitations of the research and the need for large randomised placebo-controlled trials to confirm their suspicions, and recommend that these studies include a variety of different cancer types. In the meantime, they advise people with cancer to discuss the benefits and risks of aspirin with their doctor.

 

Conclusion

The systematic review looked at 47 studies and attempted to combine the results, looking for evidence of a beneficial effect of low-dose aspirin on risk of death in people already diagnosed with cancer.

The few RCTs identified – the best-quality evidence – did not provide conclusive evidence that aspirin improves survival rates.

The rest of the studies were observational in nature, so cannot prove that aspirin reduces the risk of death from cancer. The only significant results were for a 24% reduction in risk of death from colon cancer, and a possible 11% reduced risk of death from prostate cancer. However, these results should be viewed with some caution, as several studies were omitted from the pooled analyses, as they reported different results. This means that the overall link may not be so clear-cut and more good-quality evidence is needed.

Despite widespread media reports and pictures, aspirin was not found to reduce the risk of death from breast cancer – the results could have occurred by chance.

A variety of aspirin doses were used in the different studies, which makes interpretation of the findings even more difficult.

The researchers attempted to see if aspirin had an effect on the spread of cancer, but combined the results of studies of people with colon, prostate or breast cancer. There are so many variables which cannot be accounted for in this type of analysis that it limits confidence in this result.

Aspirin does reduce the risk of stroke and heart attacks, but can also increase bleeding risk in the stomach and the brain, especially if you have uncontrolled high blood pressure. In this current review, no major bleeding was reported, but data was only available for two small trials out of 47.

No widespread recommendations should be made before we know the possible benefits of aspirin for people with cancer outweigh its risks.

If you are considering taking low-dose aspirin on a daily basis, you should discuss the pros and cons with your GP, or pharmacist, before starting.

Links To The Headlines

Aspirin could help BEAT cancer: Daily pill can 'cuts odds of dying of breast, bowel and prostate cancer by a fifth'. Daily Mail, April 21 2016

Daily aspirin can increase chance of surviving cancer. The Times, April 21 2016

Aspirin can boost chances of beating cancer by 20% – if you take it once a day. Daily Mirror, April 20 2016

Daily aspirin boosts survival in cancer patients, study shows. The Daily Telegraph, April 20 2016

Links To Science

Elwood PC, Morgan G, Pickering JE, et al. Aspirin in the Treatment of Cancer: Reductions in Metastatic Spread and in Mortality: A Systematic Review and Meta-Analyses of Published Studies. PLOS One. Published online April 20 2016

Categories: NHS Choices

Attending all-girl school linked to increased risk of eating disorders

NHS Choices - Behind the Headlines - Thu, 21/04/2016 - 17:28

"Anorexia could be 'contagious' in girls' schools," the Daily Telegraph reports, while the Mail Online claims that, "Pushy parents are driving children to eating disorders."

The study, which took place in Sweden, found that girls attending schools where more parents had a higher education and more pupils were female were more likely to be diagnosed with eating disorders, such as anorexia or bulimia, regardless of their individual circumstances.

The researchers say this is the first study to look at differences between schools as a factor in how likely girls are to develop an eating disorder.

The study used an impressively large data set from Sweden to look at records for 55,059 teenage girls who attended secondary schools in and around Stockholm. 

The researchers found the probability of a girl having an eating disorder at a school where 75% of the pupils were female and 75% of the pupils had parents with a "higher education" was 3.3%.

This is more than double that of a girl attending a school where 25% of the pupils were female and 25% had parents with a higher education.

The researchers were careful not to state that they had uncovered reasons for this trend, unlike the media.

The Telegraph speculated that all girls schools may promote a culture of "body shaming", where girls feel immense peer pressure to obtain or maintain a certain body appearance.

The Mail Online places the blame on highly educated "pushy parents" who encourage perfectionism – a trait strongly linked to eating disorders like anorexia. 

Where did the story come from?

The study was carried out by researchers from the University of Oxford, the University of Bristol, the London School of Hygiene and Tropical Medicine, Karolinksa Institutet, and University College London.

It was funded by the Wellcome Trust and Stockholm County Council. 

The study was published in the peer-reviewed journal the International Journal of Epidemiology on an open access basis, so it's free to read online.

Although the headline about "pushy parents" was not borne out by the study, the Mail Online's story was broadly accurate.

It did not, however, report the possibility that the difference in rates of eating disorders might be because more educated parents may be more likely to seek help for their children's eating disorders, meaning more girls were diagnosed. 

Similarly, The Telegraph's headline that, "Anorexia could be 'contagious' in girls' schools" is a little simplistic.

While the cultural norms of a certain institution, like a school, may contribute to eating disorder risk, the use of the term "contagious" (which, to be fair to the newspaper, was also used by the researchers) is unhelpful, as it runs the risk of stigmatising those with eating disorders.

What kind of research was this?

This was an analysis of data from a large cohort study, which used linked databases to accumulate information about girls, their parents, and the schools they attended.

Studies like this are good ways for researchers to look for and investigate links between different factors. However, they can't tell us whether one factor causes another.  

What did the research involve?

Researchers began with a big register of all children who lived in Stockholm County from 2001-11, then used the children's identification numbers to find information about their parents, records of eating disorders, schools and more.

After adjusting for individual characteristics, they looked at whether specific school characteristics – the proportion of pupils who were female and the proportion of girls whose parents were educated to degree level – affected the chances of an average girl getting an eating disorder.

The work involved building detailed mathematical models, where specific factors were included and excluded to see what effect they had on the chances of eating disorders.

Because girls are more often diagnosed with eating disorders than boys, and because having highly educated parents is known to raise individual risk of eating disorders, the researchers had to try to tease out the effect on the individual from the effect of the school.

The researchers also checked for the influence of other potential confounding factors, including family income, mental health and eating disorders among parents, average test score results, the child's weight at birth, and their number of siblings at birth.

They restricted their analysis to a first diagnosis of an eating disorder or attendance at an eating disorder clinic from the ages of 16 to 20. Schools studied were the Swedish "gymnasium" level, which pupils attend from the age of 15 to 18.  

What were the basic results?

The overall chance of being diagnosed with an eating disorder for the 55,059 girls in the study was 2.4%.

Differences between schools accounted for 2.9% (95% confidence interval [CI] 1.6 to 5.3) of the variation in rates of eating disorders between schools, meaning that the influence of factors affecting individual girls had a stronger effect.

However, after adjusting figures to take account of individual factors, school differences had a measurable effect, raising the risk of an eating disorder by almost 10% (odds ratio [OR] 1.07, 95% CI 1.01 to 1.13) for each 10% rise in the proportion of girls attending a school, and by just over 10% (OR 1.14, 95%; CI 1.09 to 1.19) for each 10% rise in the proportion of parents with a higher education.

The researchers calculated that the chances of getting an eating disorder were lower than average for girls who attended schools where only a quarter of pupils were female and only a quarter of parents had a higher education, at 1.3%. Odds were higher for girls where three-quarters of pupils were female and three-quarters of parents had a higher education, at 3.3%.

How did the researchers interpret the results?

The researchers said this was the first study to establish that school characteristics explained some of the differences in rates of eating disorders between schools.

"On average a young woman, regardless of her own background, is more likely to develop an eating disorder if she attends a school with a higher proportion of girls or of children of highly educated parents," they say.

They say that possible explanations include "the idea of ED [eating disorders] being contagious", so schools where some pupils have eating disorders are likely to see the disorder spread through peer pressure, but also that "schools' expectations around achievement" might play a part.

"Schools with more students from more educated families may have higher aspirations and exert greater demands on their students. This may encourage perfectionism, which is strongly associated with eating disorders," they say. This means that, "An aspirational school culture may inadvertently lead to increased rates of eating disorder."

Conclusion

Eating disorders are fairly common among adolescent girls, and can take a terrible toll on health that lasts throughout life. They affect bone strength and fertility, and are hard to treat and recover from.

Researching factors that might affect the risk of getting an eating disorder is important, and this study is a helpful first step in looking at ways in which schools could reduce that risk.

But this study can only tell us so much. Researchers already know that girls are more prone to eating disorders than boys and eating disorders are more common among girls whose parents have a higher education level.

What this study adds is that these things might have a cultural effect on a whole school environment, beyond the effect on individual girls with highly educated parents.

The study does not tell us the mechanisms behind the increased risk they found. As the researchers note, it could be that parents with a higher education are more likely to spot and seek help if their child gets an eating disorder.

As the figures in the study include attendance at an eating disorder clinic, as well as actual diagnoses of eating disorders, this is important. It could be that parents at some schools are more aware of eating disorder clinics than others and more likely to make use of them.

It's tempting for the media to look for a scapegoat – in the Mail Online's case, "pushy parents" – to explain the findings. But the truth is that we just don't know.

It would be sad if schools where girls are encouraged to aspire to success were criticised for inadvertently causing eating disorders. Eating disorders are very complex, with many potential interacting causes. It's not helpful to pin the blame on parents or schools who are doing their best to help their children.

If you, or someone you know, may have an eating disorder, it's important to seek help quickly. Talk to your GP or get in touch with a charity like Beat, which supports people with eating disorders.

Links To The Headlines

Pupils at all girls schools far more likely to suffer from anorexia. The Daily Telegraph, April 21 2016

Pupils at all girls schools are MORE likely to get anorexia: Pushy parents are driving children to eating disorders. Mail Online, April 21 2016

Links To Science

Bould H, De Stavola B, Magnusson C, et al. The influence of school on whether girls develop eating disorders. International Journal of Epidemiology. Published online April 20 2016

Categories: NHS Choices

UK dementia rates have fallen sharply in men

NHS Choices - Behind the Headlines - Wed, 20/04/2016 - 14:30

"Dementia rate falls as men behave themselves," The Times reports. A UK study of dementia trends over the last 20 years suggests that the number of men developing the condition has dropped significantly, possibly as a result of lifestyle changes.

The study showed an unexpectedly large fall in the number of people in the UK aged over 65 with signs of dementia between two time periods – 1989-94 and 2008-11.

There was a dramatic decrease in rates of dementia among older men, which almost halved for those aged 80 and over. Although rates for women also fell, the changes were much smaller. It is unclear why a similar strong trend was not seen in women.

Both the authors and the media speculate that positive trends in men's health – such as reduced smoking levels, improved diets, and more men taking regular exercise – could be responsible for the falling rates. While these are certainly plausible suggestions, they are unproven.

However, there is a strong body of evidence that healthy living – such as not smoking, keeping to a healthy weight, and taking regular exercise – does reduce the chances of getting dementia, although it is still no guarantee.  

Where did the story come from?

The study was carried out by researchers from Newcastle University and Cambridge University, and was funded by the Medical Research Council and the National Institute for Health Research.

It was published in the peer-reviewed journal Nature Communications on an open access basis, so it is free to read online.

The Daily Mail, The Daily Telegraph and the Sun all go with the angle that "new men", as the Telegraph quaintly calls them, are healthier, so less likely to get dementia.

The Times, somewhat patronisingly, echoes this with the claim that these days, "men behave themselves".

The Guardian and BBC News are more cautious, saying that the "most likely explanation" is improvements in male health.  

What kind of research was this?

This was a combination of two cohort studies. Both studies had two phases: a baseline, when people were interviewed and their mental health assessed, and another two years later, when the interviews were repeated.

The studies aimed to discover the proportion of people who got dementia during the two-year time period between interviews.

Researchers wanted to see if this number – called incidence – had changed. Cohort studies can find information like this, but they can't tell us much about the reasons behind the results.  

What did the research involve?

Researchers replicated a study first carried out with 7,635 people aged over 65 between 1989 and 1994 from sites around the UK.

They then used the same questions to assess the mental health of a group of 7,762 people between 2008 and 2011 from three of the areas originally studied.

In both studies, people were assessed once, then again two years later, to see if they had developed dementia. This allowed researchers to calculate the incidence of dementia, or the number of new cases per 1,000 people. They looked to see whether the incidence had changed in the two decades since the early 90s.

The researchers checked their figures for factors that could have affected the results – for example, whether people who didn't respond to the original request to be interviewed were more likely to have dementia already – and also assessed the impact of where people lived.

The original study was done in several stages, meaning that more people dropped out between interviews, so the researchers tried to account for any effect of that. 

They decided to use the same criteria for diagnosing someone with dementia that were used in the first study, even though the criteria for diagnosing dementia had changed since then. They said this was important to keep the results consistent. 

Finally, they calculated incidence rates for people by age range and sex.  

What were the basic results?

Incidence rates overall dropped from 20 cases of dementia for every 1,000 people in the early 1990s (95% confidence interval [CI] 16.9 to 23.8), to 17.7 cases per 1,000 (95% CI 15.2 to 20.9) in the more recent study.

However, looking at figures for men and women separately, the most dramatic drops in incidence were among older men. Rates almost halved for men aged 85 or over, from 71 in 1,000 (95% CI 36.5 to 140.2) to 38 in 1,000 (95% CI 22.5 to 64.2).

Rates for women declined a little in each age range, except among those aged 80 to 84, where they rose a little.

The researchers calculated how many people you would expect to get dementia each year in the UK, based on the 1991 rates but with an increased elderly population, and came up with a figure of 251,000 new cases a year. Based on the newer incidence figures, however, that dropped to 209,600 new cases of dementia a year. 

How did the researchers interpret the results?

The researchers said their findings suggest that fears of "huge increases of people with dementia" in the future may be wrong. However, they warn this might only apply to parts of the world where health has improved.

They say future investment should be directed at improving health across the whole of the life course, so that people have good circulation, plenty of opportunities to engage in society, and good education. They say this may be more cost effective than strategies to diagnose dementia early.

They questioned whether "earlier and earlier identification of at-risk states" is helpful, saying that their findings of reductions in dementia "will be offset within services by the concept of 'early' detection" and changes in diagnostic criteria.

"Individuals who were previously not diagnosed with dementia or cognitive impairment are now being tested and referred for specialist assessment of ever milder stages with unknown prognostic significance," they said. 

Conclusion

The figures from this study are striking, particularly the drop in the incidence of dementia in older men. However, we don't know what is behind this dramatic drop.

While it would be great to think that it's because men in their 80s are smoking less, exercising more and generally living healthier lives, we don't know whether this is true or if it can completely account for the big drop in dementia rates.

It's possible that the figures for men aged 80 and over are less reliable than those for younger age groups, as there were fewer men of this age interviewed.

For example, only 205 men aged over 85 were interviewed at baseline in 1991, with 110 interviewed at follow-up. The numbers for the second cohort were 364 men interviewed in 2008, with 193 interviewed at follow-up. 

These small numbers are reflected in the large confidence intervals for these results. The smaller the numbers in a specific group, the greater the chance that any perceived effect is, in fact, the result of chance.

The researchers' decision to use the 1991 study criteria for deciding whether someone had dementia has been criticised by one expert, Dr Sujoy Mukherjee, consultant psychiatrist at West London Mental Health Trust and a member of the Dementia Strategic Clinical Network.

Diagnostic criteria have changed, and people who were not diagnosed with dementia in 1991 might be seen as having dementia today. Dr Mukherjee says this could undermine the findings. But using modern criteria would have made it difficult to do a direct comparison between the two time periods.

Although it's right to be cautious about the study results and their interpretation, that doesn't change what we already know about how to reduce the risk of dementia. Keeping active, having a healthy social life, and being a healthy weight are all good ways to protect the brain in later life. 

Links To The Headlines

Dementia rate falls as men behave themselves. The Times, April 20 2016

Drop in dementia rates suggests disease can be prevented, researchers say. The Guardian, April 19 2016

Why men are leading the fight against dementia: Better diets, more exercise and quitting smoking means 'cases are a fifth lower than expected'. Daily Mail, April 20 2016

'New men' winning dementia battle as healthy lifestyles prevent 40,000 cases a year. The Daily Telegraph, April 19 2016

Dementia threat 'may be less severe' than predicted. BBC News, April 19 2016

DeMENtia drop: Chances of healthy-living males getting dementia halves. The Sun, April 20 2016

New study reveals a '20% fall in new cases of dementia' in past two decades. ITV News, April 19 2016

Links To Science

Matthews FE, Stephan BCM, Robinson L, et al. A two decade dementia incidence comparison from the Cognitive Function and Ageing Studies I and II. Nature Communications. Published online April 19 2016

Categories: NHS Choices

Natural protein 'restores memory in mice with Alzheimer's'

NHS Choices - Behind the Headlines - Tue, 19/04/2016 - 15:30

"Alzheimer's symptoms could be reversed by restoring protein in brain," The Daily Telegraph reports.

Researchers say mice with Alzheimer's disease-like symptoms showed improvement in memory tasks after being given the protein interleukin 33 (IL-33), which is thought to boost immune function.

They used mice bred to have Alzheimer's-like symptoms to investigate whether injections of IL-33 into mice was able to reduce or reverse the symptoms of dementia.

People with Alzheimer's have been found to have lower levels of IL-33. It is thought this could lead to the development of the abnormal clumps of proteins known as toxic beta-amyloid protein plaques, the characteristic hallmark of the condition.

Mice who received the protein had improved memory and brain function compared with the control group, as well as a reduction in beta-amyloid protein levels.

This is potentially very exciting as current treatments for Alzheimer's can only temporarily slow the progression of the disease, as opposed to reversing the neurological damage it causes.

Of course, the normal warnings about prematurely assuming that positive animal results will translate into similarly positive results in humans apply. 

Even if this treatment approach proves effective in humans, it remains to be seen if it would also be safe and free from significant side effects and complications.

Media estimates that it could take at least five years for this treatment to come to market – assuming it does prove safe and effective – seem reasonable.

Where did the story come from?

The study was carried out by researchers from a number of institutions, including the Hong Kong University of Science and Technology and the University of Glasgow.

Funding was provided by the Research Grants Council of Hong Kong SAR, the National Key Basic Research Program of China, a Hong Kong Research Grants Council Theme-based Research Scheme, and the SH Ho Foundation.

The study was published in the peer-reviewed journal, Proceedings of the National Academy of Sciences of the United States of America (PNAS) on an open access basis, so you can read it for free online.

This has been reported widely and accurately by the UK media, with a clear message that this is early research in mice and therefore caution should be taken – though many of the headline writers failed to pick up on this message.

Many of the reports include the somewhat world-weary, yet realistic, quote from lead author Professor Eddy Liew, who said: "Exciting as it is, there is some distance between laboratory findings and clinical applications.

"There have been enough false 'breakthroughs' in the medical field to caution us not to hold our breath until rigorous clinical trials have been done." 

What kind of research was this?

This is an experimental study in an animal model of Alzheimer's disease that aimed to investigate whether injecting the interleukin 33 (IL-33) protein into mice leads to improved dementia symptoms.

IL-33 is a cell signalling protein, and previous studies have shown that levels of a receptor to "catch" IL-33 are increased in people with mild cognitive impairment (pre-dementia).

As the name suggests, cell signalling proteins play an important role in transmitting "messages", or instructions, between cells.

This suggests that impaired IL-33 signalling could contribute to the development of the disease changes seen in Alzheimer's, such as the build-up of beta-amyloid protein plaques.

The researchers therefore speculated there may be a role for IL-33 treatment to stop the changes of Alzheimer's.

Animal studies like this are required to provide a path for further research in humans, but the findings are not directly applicable to people.  

What did the research involve?

The researchers took mice aged between 6 and 25 months bred to have brains similar to people with Alzheimer's. The mice were split into two groups: one group received IL-33 injections and the other was a control group.

IL-33 was given by injection into the abdomen for two consecutive days, after which time the two groups of mice were tested for symptoms of cognitive decline, including their:

  • learning
  • memory
  • response to stimulus
  • retrieval abilities, such as retrieval of fear memories following a fear conditioning test

These abilities were tested by putting the mice in an exploration chamber, which included features such as light beams and electric shock panels, for 15 minutes at a time on consecutive days. 

After a further two days of IL-33 treatment, the mice's brains were examined to look at the effect on amyloid plaques.  

What were the basic results?

IL-33 was found to reach the brain within 30 minutes of injection and did not affect the general health of the mice.

The IL-33 group were found to have improved memory and cognitive function compared with the control group for learning, memory, response to stimulus and retrieval abilities. There was also a reduction in protein levels and the accumulation of amyloid plaques.  

How did the researchers interpret the results?

The researchers concluded their findings indicate IL-33 is able to prevent and break down amyloid plaques, and even at late stages of the disease may represent a new treatment for Alzheimer's disease. 

Conclusion

This experimental study in mice aimed to investigate whether injecting the signalling protein interleukin 33 (IL-33) into mice leads to better outcomes in dementia.

People with Alzheimer's disease have been found to have lower levels of the IL-33 protein in the brain than those who do not have the condition. The researchers hoped symptoms could be improved, or even reversed, by restoring levels of the protein.

These preliminary results are promising. In mice, IL-33 did seem to improve learning and memory in the exploration chamber tests, and also reduced beta-amyloid protein levels and the accumulation of amyloid plaques in their brains.

However, while these findings show promise, it is very early days – caution should be taken in interpreting these findings.

Studies in humans need to be conducted to see if such a treatment has the same effect and whether it is safe.

But human studies could take years, and even then we don't know whether it would result in a licensed treatment.

As the exact cause of Alzheimer's disease is still unknown, there's no way to prevent the condition. But a good rule of thumb is "what is good for the heart is also good for the brain".

Activities known to boost your cardiovascular health may also help reduce your dementia risk. These include:

Read more about preventing dementia.

Links To The Headlines

Alzheimer's symptoms could be reversed by restoring protein in brain. The Daily Telegraph, April 19 2016

Jab 'can reverse Alzheimer's in only one week': Treatment set to be tested on humans after discovery that injections of key protein helped restore memory in mice. Mail Online, April 19 2016

Protein injection hope for Alzheimer's. BBC News, April 19 2016

Protein discovery could lead to Alzheimer's treatment. ITV News, April 19 2016

Simple injection of protein could reverse effects of Alzheimer's. The Times, April 19 2016 (subscription required)

Links To Science

Fu AKY, Hung K, Yuen MYF, et al. IL-33 ameliorates Alzheimer's disease-like pathology and cognitive decline. PNAS. Published online April 18 2016

Categories: NHS Choices

Warning issued over alarming rise in 'super-gonorrhoea' cases

NHS Choices - Behind the Headlines - Mon, 18/04/2016 - 17:00

"Doctors have expressed 'huge concern' that super-gonorrhoea has spread widely across England," BBC News reports.

Public Health England issued the warning about the rise of a strain of gonorrhoea that has developed resistance to a widely used antibiotic. 

What is gonorrhoea?

Gonorrhoea is a sexually transmitted infection (STI) caused by bacteria called Neisseria gonorrhoeae or gonococcus. It used to be known as "the clap".

The bacteria are mainly found in discharge from the penis and vaginal fluid.

It is easily passed between people through:

  • unprotected vaginal, oral or anal sex
  • sharing vibrators or other sex toys that haven't been washed or covered with a new condom each time they're used

Typical symptoms of gonorrhoea include a thick green or yellow discharge from the vagina or penis, pain when urinating, and bleeding between periods in women.

However, around 1 in 10 infected men and almost half of infected women don't experience any symptoms.

The infection can also be passed from a pregnant woman to her baby. If you're pregnant and may have gonorrhoea, it's important to get tested and treated before your baby is born. Without treatment, gonorrhoea can cause permanent blindness in a newborn baby. 

What is 'super-gonorrhoea'?

Super-gonorrhoea is a term used to describe strains of gonorrhoea that have developed a resistance against the antibiotic normally used to treat the infection – azithromycin. There is an alternative antibiotic called ceftriaxone, which is also effective.

But there are concerns that strains could also develop resistance to ceftriaxone, which would make the disease extremely challenging to treat.

Dr Gwenda Hughes, consultant scientist and head of the STI section at Public Health England, explained: "We know that the bacterium that causes gonorrhoea can rapidly develop resistance to other antibiotics that are used for treatment, so we cannot afford to be complacent.

"If strains of gonorrhoea emerge that are resistant to both azithromycin and ceftriaxone, treatment options would be limited as there is currently no new antibiotic available to treat the infection." 

What's the scale of the problem?

An outbreak of cases was first reported in Leeds in November 2014.

Additional cases have now been confirmed in the West Midlands and the south of England, five of which were in London.

This takes the total number of cases confirmed in England from November 2014 to April 2016 up to 34.

Cases have been reported both in heterosexual couples and men who have sex with men. 

How do I reduce my risk?

Dr Hughes advises that, "Everyone can significantly reduce their risk by using condoms with all new and casual partners."

Getting tested for STIs regularly can lead to early identification and treatment, as often these infections have no symptoms.

In addition, reducing the number of sexual partners you have and avoiding overlapping sexual relationships can reduce the risk of becoming infected.

If you have put yourself at risk of any STI, it is always best to seek advice from your local sexual health clinic.

Find sexual health services in your local area.  

Links To The Headlines

Super-gonorrhoea's spread 'causing huge concern'. BBC News, April 17 2016

'Super-gonorrhoea' is spreading across Britain and will become untreatable, doctors fear. The Daily Telegraph, April 17 2016

Doctors fear 'super-gonorrhoea' will become untreatable and STD will spread across the UK. Daily Mirror, April 17 2016

Doctors fear untreatable 'super-gonorrhoea' may sweep through the UK. The Sun, April 17 2016

Public Health England issues warning amid 'huge concern' as five cases of 'super-gonorrhoea' are reported in London. ITV News, April 17 2016

Categories: NHS Choices

Child head injuries could harm relationship with parents

NHS Choices - Behind the Headlines - Mon, 18/04/2016 - 14:30

"A simple bang on the head can alter a child's relationship with their parents claim academics," the Daily Mail reports.

A Canadian study found children who had experienced even a mild traumatic head injury, may have developed changes to their mood and behaviour.

Mild head injuries are common in younger children and may carry a risk to their developing brains. The study team were concerned that the psychological effects of head injuries may be underestimated.

The study aimed to assess the social and developmental effects of a mild head injury on 47 young children aged under five years. The group was compared to groups of children who'd had an orthopaedic injury (e.g. a fractured bone) or no injury.

Six months after the injury, researchers observed the child and their parents during 45 minutes of play or other activities, and rated the interactions among the head injury group as significantly poorer than the no injury group. There were no differences from the orthopaedic group.

There are several limitations to this study, including lack of observation prior to the accident to compare against. We also do not know whether these score differences have any meaningful implications for the child's long-term development, particularly given that the parent's reported no change in their interactions with their child.

Parents should not be overly concerned by these findings. However, they know their child best and if they think a head injury could be having longer-term effects on their child, they should seek medical advice.

 

Where did the story come from?

The study was carried out by researchers from Ste-Justine Research Centre and the University of Montreal, Quebec, in Canada, and was published in the peer-reviewed Journal of Neuropsychology. No sources of financial support are reported.

The Daily Mail's coverage may cause undue concern to parents and would have benefited from noting some of the limitations of this research, such as the lack of long-term follow-up assessments.

 

What kind of research was this?

This was a cohort study to observe the quality of the parent-child relationship for young children (18 months to five years) who had experienced a mild traumatic brain injury (TBI), caused by, for example, a fall or accident that results in a blow or jolt to the head.

The researchers say that mild TBI, or concussion only, where there are no signs of brain damage on imaging scans, accounts for the vast majority of all TBIs. In children under the age of five, TBIs are said to affect nearly 2 in 100 children every year.

The size and weight of the child's head in relation to the rest of their body reduces the control they have when trying to minimise the impact of a force/blow to the head. Furthermore, as the child's brain is still developing, they are thought to be particularly vulnerable to the effects of trauma. 

The researchers considered that because parent-child relationships form the centre of the child's social environment, they are the ideal setting to observe the possible adverse effects of mild TBI on a child's functioning.

 

What did the research involve?

The study recruited 130 children from an emergency department. They were aged 18 to 60 months and comprised three groups:

  • 47 who'd had an accidental mild TBI
  • 27 who'd had an accidental orthopaedic injury, such as a bone fracture
  • a control group of 56 children who'd had no injury

They excluded children with other confounding characteristics that could influence the results, such as those born premature, diagnosed with other significant physical or psychological conditions (including congenital), or previous head injury. 

Requirements for mild TBI were that the head trauma involved:

  • acceleration-deceleration (e.g. falling and hitting your head)
  • their Glasgow Coma Scale (GCS) score was 13-15 (15 is the maximum and equates to full normal response); the GCS is a well-validated scoring system for assessing neurological damage resulting from brain injury
  • they'd experienced at least one symptom such as loss of consciousness, confusion, irritability, drowsiness, poor balance or vomiting  
  • there were no signs of damage on brain imaging

Parents completed questionnaires on the child's pre-injury behaviour and environment. Six months after injury the researchers collected follow-up information via questionnaires, and also conducted a three-hour observation assessment with the child and their parent.

The assessments used numerous validated scales. There were two main outcome measures – the Mutually Responsive Orientation (MRO) scale and the Parental-Stress Index. The former measures the quality of child-parent interactions over 45 minutes when involved in different activities, such as playing with toys or eating a snack. The Parental-Stress Index is a self-reported questionnaire on parental distress, parent–child dysfunctional interaction and child characteristics, with a higher score indicating a poor bond.

The researchers followed up 94% of the original sample.

 

What were the basic results?

The main results reported relate to the MRO score, which focuses on parent-child exchanges. Children in the mild TBI group scored significantly lower at follow-up than children in the non-injured control group for all three subscales of the MRO score – communication, co-operation and emotion. There was no difference between the orthopaedic injury group and the other two groups.

There were reportedly no differences between groups in self-reported parent-child interaction on the Parental-Stress Index. The researchers interpret this to mean that observational measures may be more sensitive.

 

How did the researchers interpret the results?

The researchers conclude that their findings, "have implications for children's post-injury social development and highlight the importance of monitoring social outcomes even after minor head injuries."

 

Conclusion

This observational study comparing groups of young children in Canada who'd experienced mild TBI, orthopaedic injury or no injury finds that the MRO scores were lower after injury in the TBI group than the uninjured group.

However, before leaping to the conclusion that children who have suffered a mild head injury are going to have impaired development and poor social interactions, there are several important points to bear in mind:

  • Though parents were said to have reported the child's pre-injury function, we have no observational assessments from before the injury, so don't know that they significantly differed from before.
  • There was no difference in the parents' report of their interactions with their child on the Parental-Stress Index. The researchers interpret this to mean that observational measures on the MRO may be more sensitive, but it could be debateable what clinical significance the between-group differences on the MRO actually have. For example, the TBI group had lower scores than the no injury group. Does that mean there's going to be any meaningful difference in their development or social interactions? It would be useful to follow these children up a year or a few years down the line, to see if these apparent differences at six months persisted.    
  • There was a relatively small number of children in the different groups. The same differences may not have been observed if there were a larger selection of children or they had been recruited in different ways. For example, this sample of children with mild TBI had all presented to the emergency department. There may be many more children who experience a mild knock to the head, but their parents don't take them to hospital. Therefore, it is difficult to know which children this group can be generalised to.

Overall, the study is a useful addition to the literature on the possible effects of mild TBI in young children. However, it does not provide good evidence that suffering a mild brain injury affects the quality of the child's relationship with their parents.

If you are concerned that your child's behaviour, mood and attitude may have changed after a recent head injury, you should contact your GP for advice as a precaution.

Links To The Headlines

A simple bang on the head can alter a child's relationship with their parents claim academics. Daily Mail, April 18 2016

Links To Science

Lalonde G, Bernier A, Beaudoin C, et al. Investigating social functioning after early mild TBI: the quality of parent-child interactions. Journal of Neuropsychology. Published online March 24 2016

 

Categories: NHS Choices

Zika virus 'does cause birth defects'

NHS Choices - Behind the Headlines - Thu, 14/04/2016 - 17:30

"The US Centers for Disease Control and Prevention … has confirmed that the Zika virus causes severe birth defects," BBC News reports.

The Centers for Disease Control and Prevention (CDC) has concluded that "a causal relationship exists between prenatal Zika virus infection and microcephaly", where babies are born with unusually small heads and brains.

The media coverage explains that despite strong suspicions, scientists had been cautious about stating that the mosquito-borne Zika virus was behind the spike in cases of microcephaly until they had sufficient proof.  

What is the basis for these reports?

Experts from the CDC have published a summary of the evidence into the link between the Zika virus and brain malformations, including microcephaly.

They weighed the evidence against two different sets of criteria used to work out whether something that happened in pregnancy, such as taking a drug or getting an infection, was a cause of birth defects.

The summary, published on an open-access basis in the peer-reviewed New England Journal of Medicine, concluded that, "A causal relationship exists between prenatal Zika virus infection and microcephaly and other serious brain anomalies."

The authors of the summary, who all work for the CDC, then issued a statement in which they said: "It is now clear that the virus causes microcephaly." 

What are Zika virus and microcephaly?

Zika virus is carried by mosquitoes and can also be passed on through sexual contact.

In most people, it causes a mild illness with a raised temperature, rash, joint pain or conjunctivitis, although many people have no symptoms at all.

However, doctors noted an increase in cases of microcephaly, a rare birth defect where the brain does not grow as it should, about nine months after the virus was first identified in Brazil in 2015.

Microcephaly happens when brain development is affected during pregnancy. The brain ceases to grow at the rate it should, and the skull also stops growing properly.

This means the baby's head is much smaller than it should be and the brain is not properly developed. The child is likely to have serious intellectual difficulties as a result.  

Why do scientists think Zika virus causes microcephaly?

The scientists looked at five main questions:

1. Were women infected with Zika virus at a stage in their pregnancy where it could have caused microcephaly?

Yes. Studies showed this was the case, either by the timing of symptoms or by the timing of when the women travelled to areas where Zika virus was common.

2. Are there at least two studies of groups of women that show an association between those who had the virus and those who had babies with microcephaly?

Although some studies exist, the authors said they are too small to rely on completely. The researchers judged this question to only be partially answered.

3. Is the birth defect distinctive and clearly identifiable?

Yes. The researchers said the characteristics of babies affected by microcephaly in this outbreak were very clear and consistent with the stage of development at which the infections had occurred.

4. Is this a rare birth defect, and is Zika virus infection also rare?

Yes. This means the chance of both happening to one person by unlucky coincidence is very low. The birth defect is rare. Although many women were infected with Zika virus during the Brazil outbreak, women infected who travelled to Brazil from unaffected areas also went on to have babies with microcephaly. But for these women, Zika infection was rare.

5. Does the association make biological sense?

Yes. Crucially, scientists have now identified Zika virus in the brains of babies with microcephaly, and have shown in the laboratory that Zika virus infects and kills or slows growth of nerve cells. This provides "strong biologic plausibility", the researchers say.

Conclusion

The scientists say that, on balance, "we suggest that sufficient evidence has accumulated" to say that Zika is the cause of the current spike of microcephaly cases.

They add that researchers, "have been unable to identify alternative hypotheses" for the increase in microcephaly. 

How does Zika and microcephaly affect you?

Public health advice about Zika virus has not changed. At present, Zika virus is thought to be transmitted by mosquitoes in the Caribbean, Central and South America, the Pacific Islands, Vietnam, the Philippines and Cape Verde. See an updated list here.

The Royal College of Obstetricians and Gynaecologists (RCOG) recommends that pregnant women should continue to avoid travelling to areas where Zika is actively spreading.

For more information and advice, read our page on the Zika virus.

Links To The Headlines

US health experts confirm that Zika causes birth defects. BBC News, April 13 2016

Zika virus confirmed as cause of microcephaly birth defect, CDC says. The Guardian, April 13 2016

Zika virus DEFINITELY causes the birth defect microcephaly, CDC says. Mail Online, April 13 2016

Links To Science

Rasmussen SA, Jamieson DJ, Honein MA, Petersen LR. Zika Virus and Birth Defects – Reviewing the Evidence for Causality. The New England Journal of Medicine. Published online April 13 2016

Categories: NHS Choices

Would you trust a smartphone app as a contraceptive?

NHS Choices - Behind the Headlines - Thu, 14/04/2016 - 08:28

"An innovative new app might provide a more effective form of birth control than the contraceptive pill," The Sun reports.

The Natural Cycles fertility app combines the use of a thermometer to measure body temperature with calendar calculating methods – often referred to as the rhythm method – to work out the days when a woman would be at high or low risk of pregnancy.

More than 4,000 women were included in this Swedish study looking at how effective the app is at preventing pregnancy.

A total of 143 unplanned pregnancies occurred during the study period, 10 of which were the result of the app falsely indicating a safe day.

Data collected by the app was used to work out that, if used exactly as advised, 5 women out of every 1,000 will accidentally become pregnant, and 7 out of every 100 women will become pregnant for "typical use" (not using the app correctly), each year.

This app may be attractive for women who are unwilling to use other forms of contraception, possibly for religious or cultural reasons, or because they have concerns about the side effects of hormonal contraception.

This app may also help indicate the best days to try to conceive.

But an obvious disadvantage of this contraceptive method is that the app does not protect against sexually transmitted infections in the same way as a condom.

Further research weighing an app like this against established contraceptive methods would be required to confirm whether its effectiveness is comparable. 

Where did the story come from?

The study was carried out by researchers from the manufacturer of the application, Natural Cycles Nordic AB, along with the Karolinska Institutet and University Hospital, Stockholm.

Funding was provided by Natural Cycles Nordic AB.

There is a conflict of interest with this study, as the lead authors, Elina Scherwitzl and Raoul Scherwitzl, created the app and founded the company with stock ownership, while another author, Jonas Sellberg is employed by Natural Cycles Nordic AB.

The study was published in the peer-reviewed European Journal of Contraception and Reproductive Health Care.

It has been reported on accurately in the media, with statistical comparisons made between the effectiveness of the app and the effectiveness of the contraceptive pill.

The Daily Telegraph quoted the app's creators, who said: "The algorithm behind the app learns about each individual woman's temperature fluctuations over time, so becomes more accurate as you use it more frequently."

They went on to say: "You say what your goal is when you start the app, so if you are planning a pregnancy rather than preventing, we identify the most fertile days and flag if you need to see a fertility specialist."

What kind of research was this?

This was a retrospective data analysis study that aimed to evaluate the effectiveness of a fertility awareness-based method, supported by a mobile-based application, to prevent unwanted pregnancies as a method of natural birth control.

Retrospective studies are flawed in that the data collected was not intended for such analyses and may not always give an accurate representation.

What did the research involve?

The researchers included data from fertile women aged 18 to 45 who were using a mobile-based application, Natural Cycles, as a contraceptive method. Subscription to the service, including a thermometer, cost €50.

Women included in the analysis had to meet certain criteria. They had to have:

  • accessed the app for at least three months during the study
  • entered data for a total of at least 20 days
  • not planned a pregnancy during the study period

At the beginning of the study women filled out a questionnaire related to their cycle, previous contraceptive use, height and weight. An additional optional questionnaire was sent via email three weeks before the end of the study.

Women entered their date of menstruation and body temperature recordings into the app until the end of the study, or until they dropped out because they were pregnant or had stopped using the method.

The data entered was then processed by the app to compute red (unsafe) or green (safe) days to indicate the risk of getting pregnant. The app considered the different phases of a woman's cycle and the associated changes in body temperature when computing risk.

Evaluation of the app as a contraceptive method was determined by the number of pregnancies identified from a positive pregnancy test result being entered, the algorithm detecting a pregnancy, or the online questionnaire.

All users considered potentially pregnant by the algorithm were classified as pregnant in this study, even if they failed to confirm with a pregnancy test, as requested by the app, to provide the most conservative estimates. 

Cases were considered unknown if it was not possible to detect a pregnancy with any of these methods. If a green day had been given within the fertile phase of a cycle where a woman had become pregnant, this was considered a failure.

Data collected was used to work out a Pearl Index, a measure of contraceptive effectiveness. A high Pearl Index means there is a high chance of unintentionally getting pregnant, while a low value means there is a low chance.

What were the basic results?

A total of 4,054 women tested the app, and 483,221 daily entries were analysed. The drop-out rate before the end of the study was high, at 1,397 women (34%).

The number of identified unplanned pregnancies was 143. Of these, 123 were positive test entries into the app, while 15 were detected with the algorithm and 5 were found through the survey.

Ten of the pregnancies were because the app falsely attributed a safe day within the fertile window. This indicates that if used correctly all the time, the application has a Pearl Index of 0.5, meaning 5 women out of every 1,000 will accidentally become pregnant each year.

For "typical use" – where the app is not used correctly – the Pearl Index was 7, which means that 7 out of every 100 women will experience accidental pregnancies each year.

The most conservative estimate, attributing a pregnant outcome to all 61 women for whom the pregnancy outcome was not known, gave a Pearl Index of 9.8 – 10 women out of every 100 each year.

Half of the pregnant women (51%) had logged unprotected sex during the fertile phase.

How did the researchers interpret the results?

The researchers concluded: "The application appears to improve the effectiveness of fertility awareness-based methods and can be used to prevent pregnancies if couples consistently protect themselves on fertile days."

Conclusion

This was a retrospective data analysis study that aimed to evaluate the effectiveness of a mobile-based app to prevent unwanted pregnancies as a method of natural birth control.

The app used data entered by the women to work out days when there was a high or low risk of becoming pregnant in the absence of hormonal or barrier contraception. 

The app was calculated to have a Pearl Index of 0.5, meaning 5 women out of every 1,000 will accidentally become pregnant each year. The Pearl Index was 7 for typical use, which means 7 out of every 100 women will experience accidental pregnancies each year.

Natural methods of contraception are popular for those who do want to use other methods of contraception. An app like this helps to keep track of which days are risky and when it would be better to abstain from unprotected sex.

But this study does have limitations. The retrospective design means data was not collected to specifically answer this question and may not be fit for purpose.

Most of the women in the study were aged 20 to 35, and therefore the findings may not apply to other age groups. 

The participants in this study purchased membership and were obviously keen to try this method. Their usage may not be a true indication of the effectiveness of this type of app if it was available for free.

Even here, where the app was purchased, a third of the women stopped using it, which is a much higher drop-out rate than other methods, such as the contraceptive pill. Reasons for stopping using the app were not provided in the study write-up.

In addition to helping women to avoid becoming pregnant, this app might also help indicate the best days to try to conceive. The authors mention that these days are underestimated by the app, but it may still help, provided women remember to enter details correctly.

A head-to-head randomised trial comparing such an app with established contraceptive methods would be required to establish how effective it is as a method of birth control, and would also be a better design to find out whether an app can replace the pill, as the headlines have stated.

However effective an application may be, it will not protect you against sexually transmitted infections, unlike the low-tech – but very reliable – condom.

Links To The Headlines

Sex at the click of a button: New fertility app is said to be just as effective as the contraceptive pill. The Sun, April 13 2016

I've tried the app that's 'as reliable' as the contraceptive pill - and I'm not pregnant yet. The Daily Telegraph, April 13 2016

This app is just as effective as the contraceptive pill at preventing pregnancy. Metro, April 13 2016

Natural Cycles fertility app could REPLACE contraceptive pill, new study claims. Daily Express, April 13 2016

Links To Science

Scherwitzl EB, Danielsson KG, Sellberg KA, Scherwitzl R. Fertility awareness-based mobile application for contraception. The European Journal of Contraception & Reproductive Health Care. Published online March 22 2016

Categories: NHS Choices

Study argues ditching butter for veg oil won't prevent heart disease

NHS Choices - Behind the Headlines - Wed, 13/04/2016 - 17:30

"Ditching butter for veg oil may not be better for heart," the Daily Mail reports.

An analysis of previously unpublished data from the 1960s and 70s found no benefit in replacing sources of saturated fats with vegetable oils.

The original study was conducted from 1968 to 1973 in six US psychiatric state hospitals and a nursing home. People were randomly assigned to eat a diet that switched saturated fat with vegetable oil rich in linoleic acid, or a control diet including saturated fat plus linoleic acid for about a year. Researchers looked at the data from more than 2,000 participants over a maximum follow-up period of four years.

Both diets reduced cholesterol levels, though the effect was greater for the diet with vegetable oil. In both groups, lower cholesterol levels were associated with an increased risk of death for people aged 65 or over. It is not clear that this was due to the diet, as it occurred in both groups, and as there were such small numbers, the findings are not reliable.

The study population – people staying in a nursing home or a psychiatric hospital – are not representative of the population at large, limiting confidence in the findings.

Since the 1960s and 70s, large randomised controlled trials (RCTs) have shown that lowering cholesterol with statins reduces the risk of death.

This study does not conclude that butter is good for you, but does add to the debate about dietary composition.

Where did the story come from?

The study was carried out by researchers from the National Institute on Alcohol Abuse and Alcoholism, the University of North Carolina, Medtronic (in Minneapolis), the Mayo Clinic, the University of Illinois at Chicago, and the UNC Gillings School of Global Public Health.

It was funded by the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, and the University of North Carolina Program on Integrative Medicine.

The study was published in the peer-reviewed medical journal the BMJ on an open-access basis, so you can read it for free online.

In general, the UK media reported the study accurately and put the results into context, providing helpful and balanced comments from experts in the field, both for and against the arguments put forward in the study.

However, there was little coverage of the limitations of the research, such as the unrepresentative nature of the participants.

 

What kind of research was this?

This was a re-evaluation of an RCT conducted in the US from 1968 to 1973 and a systematic review and meta-analysis to put the results into context. The RCT aimed to see if a diet replacing saturated fat with vegetable oil rich in linoleic acid could reduce cardiovascular disease and deaths.

This type of study design is considered to be the gold standard, but in this case there are numerous limitations, including the short length of follow-up for determining these outcomes. In addition, the researchers were not able to access all of the data, so their main analysis is based on a small number of participants.

 

What did the research involve?

The researchers analysed published and unpublished data from the RCT.

This was a double-blinded RCT conducted in a nursing home and six state psychiatric hospitals. A total of 9,570 people were randomly assigned to eat a diet that was low in saturated fat, but high in linoleic acid-rich vegetable oil, or a control diet that had the same amount of saturated fat used before the study, but with an increase in linoleic acid. This control diet used common margarine and shortening (butter or lard).

The intervention diet used liquid corn oil instead of cooking fats and also added this to salad dressings, "filled beef" (lean ground beef with added oil), "filled milk" and "filled cheeses". This diet reduced the saturated fat from 18.5% to 9.2% of calories consumed. Both diets were designed to look the same, and the study participants and medical staff did not know which diet they were eating.

The diets were eaten for an average of 460 days.

Data was used in this re-analysis from a subset of 2,355 participants who had followed the diet for over a year, had regular cholesterol measurements and had follow-up data for three years.

The researchers analysed the results to take into account some common confounding factors, such as:

  • baseline cholesterol
  • age
  • sex
  • body mass index (BMI)
  • systolic blood pressure (the pressure of the blood when the heart beats to pump blood out)
  • their assessment of adherence to the diet

They then performed a systematic review and meta-analysis of any RCT that compared diets using vegetable oil in place of saturated fat and no other intervention.

 

What were the basic results? Re-analysis of RCT

Based on a subset of 2,355 people:

  • The low saturated fat diet significantly reduced the level of cholesterol in the blood by 13.8% compared to the control diet, which lowered cholesterol by just 1%.
  • In both groups, for each 0.78mm/l reduction in cholesterol, there was a 22% higher risk of death from any cause (hazard ratio [HR] 1.22, 95% confidence interval [CI] 1.14 to 1.32). This statistic appeared to be driven by a 35% higher risk for 595 people aged 65 years or more at the start of the study (HR 1.35, 95% CI 1.18 to 1.54).
  • There was no association between cholesterol reduction and death for the 1,760 people aged under 65. This was based on 149 deaths.

The researchers reported that a thesis on the RCT written in 1981 found that, overall, the low saturated fat diet did not reduce the risk of death compared to the control diet over the next four years and may have increased the risk of death in people aged 65 or over. However, the researchers did not have access to the raw data to be able to confirm these findings, or whether they were statistically significant.

There was insufficient autopsy information for accurate analysis of the effect of the diets on heart attacks or atherosclerosis (hardening of the arteries).

Systematic review and meta-analysis

Five RCTs including 10,808 participants were identified that compared a diet substituting saturated fats with vegetable oils rich in linoleic acid. Pooling the results, there was no difference between the diets in terms of death from coronary heart disease (HR 1.13, 95% CI 0.83 to 1.54) or death from any cause (HR 1.07, 95% CI 0.90 to 1.27).

 

How did the researchers interpret the results?

The researchers concluded from the available evidence that, "replacement of saturated fat in the diet with linoleic acid effectively lowers serum cholesterol but does not support the hypothesis that this translates to a lower risk of death from coronary heart disease or all causes".

They also criticised the fact that some of the data from the RCT was unpublished and say that this has "contributed to overestimation of the benefits of replacing saturated fat with vegetable oils rich in linoleic acid".

 

Conclusion

This re-evaluation of some of the data from an old RCT has found that both diets reduced cholesterol levels, though the effect was greater for the diet with vegetable oil. In both groups, lower cholesterol levels were associated with an increased risk of death for people aged 65 or over. It is not clear that this was due to the diet, as it occurred in both groups, and as this was just based on 149 deaths over a relatively short follow-up period, this limits the reliability of the findings.

Cholesterol levels can reduce due to illness, and there was a lack of information about what other illnesses any of the participants had, why they were in the psychiatric state hospitals, what medication they may have been taking and if they smoked. These factors limit our confidence in the findings of this study.

Other limitations include the actual amount of food that was consumed. The study design meant that participants were assumed to have eaten the food on their tray, and not to have eaten if they did not collect their tray. In addition, the study is not able to take into account any other food that the people may have eaten from visitors or the effect of their diet over their lifetime. There was also a wide variation in the diets between the hospitals.

The original study was conducted more than 45 years ago, before statins were available. Since then, large well-conducted RCTs in the general population have shown that lowering cholesterol with statins reduces the risk of death.

This study does not conclude that butter is good for you, but does add to the ongoing debate about the best dietary composition.

Due to the limitations of the study, it should not been seen as "proof" that the current guidelines regarding saturated fats are flawed. The current UK health guidelines recommend that:

  • the average man should eat no more than 30g of saturated fat a day
  • the average woman should eat no more than 20g of saturated fat a day

These guidelines may well change after the publication of the Scientific Advisory Committee on Nutrition's evidence review on saturated fats, expected in 2017. But until then, we would recommend erring on the side of caution.

Links To The Headlines

Ditching butter for veg oil may not be better for heart: Fresh research finds drop in cholesterol has no effect on the risk of heart disease or death. Daily Mail, April 13 2016

Replacing animal fat in diet may not reduce heart risk, says study. The Guardian, April 13 2016

Butter is no more deadly than vegetable oil, study finds. The Daily Telegraph, April 13 2016

Links To Science

Ramsden CE, Zamora D, Majchrzak-Hong S, et al. Re-evaluation of the traditional diet-heart hypothesis: analysis of recovered data from Minnesota Coronary Experiment (1968-73). BMJ. Published online April 12 2016

Categories: NHS Choices

Obesity epidemic blamed for rise in womb cancer

NHS Choices - Behind the Headlines - Wed, 13/04/2016 - 14:30

"Obesity 'likely culprit' behind womb cancer rise," reports BBC News.

Cancer Research UK has released data showing a marked increase in cases of womb cancer over the last two decades, and it seems obesity could be the reason for the rise.

 

The statistics on womb cancer

Data compiled by Cancer Research UK shows that during the mid-1990s there were around 4,800 new cases of womb cancer diagnosed in the UK each year. This figure has now risen to around 9,000 cases per year – an 87.5% increase in incidence rates.

This upward trend in womb cancer rates matches a similar trend in the rates of obesity in UK women, which has risen from 16.4% in 1993 to 25.9% in 2011.

 

Warning signs of womb cancer

The most common symptom of womb cancer is abnormal bleeding from the vagina.

Bleeding may start as light bleeding accompanied by a watery discharge, which may get heavier over time. Most women diagnosed with womb cancer have been through the menopause, so any vaginal bleeding will be unusual.

While unusual vaginal bleeding can have a wide range of causes, it is a symptom that always needs further assessment. See your GP as soon as possible.

Read more about the symptoms of womb cancer.

Survival rates for womb cancer are relatively good. More than 75 out of every 100 women (75%) will survive for 10 years or more after diagnosis. Many of these women will have been cured of their cancer.

 

Obesity and womb cancer

There are three main hypotheses for why obesity may increase a woman's risk of womb cancer:

  • oestrogen – fat cells can produce excess amounts of the hormone oestrogen, which may stimulate abnormal cell growth
  • insulin – this fat-associated hormone has also been linked to abnormal cell growth
  • inflammation – obesity can increase the amount of a type of immune cell known as macrophages and these can encourage cells to divide – yet again increasing the risk of abnormal cell growth

Of course, it could be the case that all three factors are involved.

 

Preventing womb cancer

One of the most effective ways of reducing your risk of womb cancer is to achieve or maintain a healthy weight, through a combination of exercise and a healthy diet. This should also reduce your risk of type 2 diabetes, which is another risk factor for womb cancer.

The NHS Choices Weight Loss plan can help you lose weight in a safe and sustainable way. 

Links To The Headlines

Obesity 'likely culprit' behind womb cancer rise. BBC News, April 13 2016

Soaring obesity in women causes womb cancer cases to DOUBLE in just 20 years. Mail Online, April 13 2016

Obesity epidemic is fuelling rise in womb cancer, charity warns. The Guardian, April 13 2016

Soaring obesity in UK fuels sharp rise in womb cancer. The Daily Telegraph, April 13 2016

Categories: NHS Choices

Mystery of the 13 people with 'superhero DNA'

NHS Choices - Behind the Headlines - Tue, 12/04/2016 - 11:28

"Some people appear to be born with 'superhero DNA' that cancels out genetic diseases like cystic fibrosis," BBC News reports.

A study of more than 500,000 people found 13 people who should have developed genetic conditions, but apparently didn't.

The study turned on its head the traditional use of genetics by looking for healthy people whose genomes contained mutations in single genes believed to cause childhood diseases – such as cystic fibrosis – in everyone with that mutation. Or, as one of the researchers put it, "Study the healthy, don't just study the sick."

The researchers chose childhood diseases, as most people in genetic surveys are adults, so the disease should have developed by then.

Ideally, the researchers wanted to find out what it was about these people that made them resistant to the disease mutations. However, they cannot re-contact the individuals because the study protocols stated that all survey data would remain anonymous.

This not only makes it hard to follow up on possible causes, it also means that researchers cannot check they are truly resistant to the disease, rather than there being any simpler cause, such as errors in the records.

While this study raises more questions than answers, it does illustrate the potential benefits that large, population-scale, genetic surveys may bring.

In the UK, a promising project is the UK Biobank – a charitable project that recruited 500,000 people aged 40-69 in 2006-10, to look at how genetics impacts on health outcomes.

 

Where did the story come from?

The study was carried out by researchers from the Icahn School of Medicine at Mount Sinai, New York; 23andMe; BGI-Shenzhen; The Children's Hospital of Philadelphia; Lund University; Ontario Institute for Cancer Research; Sage Bionetworks; iCarbonX; and Boolean Biotech Inc.

No funding information was available. Several of the authors work for commercial gene sequencing companies, which means they have a financial interest in the results. The study was published in the peer-reviewed journal Nature Biotechnology.

The UK media, on the whole, did a good job of accurately reporting the study. However, they did not all point out that the results could be caused by recording errors, as the researchers were unable to contact the participants.

The Mail Online's use of a photo of the mutant superhero Mystique, from the X-Men series of comics and films, was a little fanciful. While the 13 individuals identified in the study may have an impressive level of "genetic immunity", we doubt that extends to shape-shifting abilities.

 

What kind of research was this?

This was a retrospective analysis of genome data collected for a variety of purposes, including commercial "disease scan" services and academic studies. The researchers had access to varying levels of genetic detail from the different studies, and to records of people's self-reported medical conditions. They wanted to find individuals who had genetic variants that would usually have caused one of a number of serious diseases that start in childhood, but who did not report having that disease.

 

What did the research involve?

Researchers screened 589,306 genomes from 12 different databases, looking for mutations in 874 genes believed to cause 584 diseases. They compared the disease mutations to records showing whether people said they'd had the diseases.

They filtered out gene mutations where the candidate gene was only weakly linked to the disease, or where the disease is not thought to affect everyone who carries the gene, or where the disease was mild enough that it could have gone unnoticed. The aim was to find people with a genetic mutation that the researchers were confident should have caused a serious illness before adulthood, but which the people involved had not reported having.

The researchers worked with different levels of detail, from whole genome genotyped cohorts to whole genome sequencing cohorts. Genotyping means searching a genome for known genetic variants, while sequencing means determining the exact sequence of a length of DNA. Sequencing a whole genotype is more difficult and expensive. They were unable to contact the people identified as being potentially resistant to their genetic mutation, because consent forms for the original genome sequencing did not allow later researchers to identify and contact the individuals.

 

What were the basic results?

The researchers say they found 13 people with mutations to one of eight inherited (usually rare) childhood diseases, which would be expected to cause serious disease before the person was 18. These were:

  • cystic fibrosis – which causes problems including excessive mucus in the lungs
  • Smith-Lemli-Opitz Syndrome – a metabolic disorder that prevents normal growth and intellectual development
  • familial dysautonomia – which prevents the nervous system from working properly
  • epidermolysis bullosa simplex – which causes skin blistering
  • Pfeiffer Syndrome – which causes skull deformity
  • autoimmune polyendocrinopathy syndrome – which causes a steep drop in the body’s production of hormones
  • acampomelic campomelic dysplasia – which affects bone growth
  • atelosteogenesis – which also affects bone growth

 

How did the researchers interpret the results?

The researchers say the study opens the possibility that "genetic modifiers may be more common than believed," because they found people with genes thought to be "completely penetrant" – i.e. to always cause disease – who nonetheless did not show signs of disease.

They say that individuals who show possible resilience to penetrant genes are still "extremely rare," so future studies will need to look at very large groups of genomes to find any. They add that future studies should allow researchers to contact people after the study has ended, so that findings can be investigated and followed up.

They say that their inability to contact individuals means they "cannot exclude straightforward explanations," including "somatic mosaicism," which is when genes are expressed in some cells of the body, but not others.

 

Conclusion

The researchers have presented some intriguing results, but their inability to contact the individuals identified in the study puts the results in question. As well as the explanation the researchers put forward, it's possible that the results are simply due to mistakes in the records.

The researchers hoped to be able to identify conditions (genetic or environmental) which might protect an individual from a disease such as cystic fibrosis, which they are genetically programmed to develop. However, the current study does not even confirm that such individuals exist, never mind help us to understand possible causes. Sadly, the practical application of the research is likely to be many years away.

This type of research is also very expensive. The researchers said they would ideally use whole genome sequencing, as opposed to the cheaper targeted sequencing used by most commercial firms, but that this would cost up to $1,500 per sample, which would reduce the numbers that could be screened.

Though the researchers and media have lamented the inability to confirm the findings by contacting the individuals, this is a tricky area that should not be taken lightly. Genetic counselling is recommended both before and after any genetic tests, for the person to decide what level of detail they want to find out. In this case, the news was likely to be good, but in many cases the news may be devastating or lead to unnecessary anxiety about the future for themselves or their offspring. There may also be health and life insurance implications.

While the research suggests a new way of looking at genetics and disease, it's hard to see a treatment for any disease based on this emerging in the short term.

The researchers have announced that they have launched a US-based project, called The Resilience Project, which aims to build upon the work of this study by hopefully identifying named volunteers with a proven genetic resilience. It will be interesting to see what insights the project may uncover.  

Links To The Headlines

'Superhero DNA' keeps diseases at bay. BBC News, April 11 2016

Are YOU a genetic 'superhero'? Doctors discover 13 people who are resistant to severe inherited diseases - and there may be more. Mail Online, April 12 2016

Scientists search for 13 people to solve genetic mutation mystery. The Guardian, April 11 2016

Links To Science

Chen R, Shi L, Hakenberg J, et al. Analysis of 589,306 genomes identifies individuals resilient to severe Mendelian childhood diseases. Nature Biotechnology. Published online April 11 2016

 

Categories: NHS Choices

Anti-smoking drug may also help combat sugar cravings

NHS Choices - Behind the Headlines - Mon, 11/04/2016 - 14:30

"Anti-smoking drugs could stub out your sugar cravings," the Daily Mail reports.

A study in rats suggests that varenicline (Champix), used to relieve nicotine cravings, could also help reduce the desire to consume sugary foods and drinks.

Varenicline targets what are known as the "reward pathways" of the brain. These are areas that respond to certain stimuli, which can range from illegal drugs, sex or gambling to sugary foods.

They react by releasing more of the "feel-good" neurotransmitter dopamine, which can stimulate feelings of pleasure.

The smoking cessation drug varenicline blocks receptors in the pathway, preventing nicotine from stimulating the same reward and response cycle. The researchers wanted to see if it would work the way same with sugar.

Rats were given sugar solution for 4 or 12 weeks, and when they were given varenicline after this time it reduced their sugar consumption for 30 minutes. The research provides evidence that sugar consumption involves the same reward pathway as other potentially addictive substances, such as nicotine – at least in rats.

The drug would need to undergo testing to see if it was similarly effective for excessive sugar consumption in humans, if the benefits outweighed the risks of the drug, and also whether it offered any advantage over other standard approaches to treating obesity.

Overall, this is interesting research, but varenicline is currently only licensed for smoking cessation in humans. Whether it may or may not have a future role in sugar addiction is unknown.

 

Where did the story come from?

The study was carried out by researchers from the Queensland University of Technology, Brisbane, and SRI International in California. Funding was provided by the Australian Research Council, National Health & Medical Research Council, and the National Institute of Health.

The study was published in the peer-reviewed scientific journal PLOS One. This is an open-access journal, so the study is freely available to read online.

The Mail's coverage is highly premature, with claims that: "Discovery could prove a significant breakthrough in the war on obesity". Despite calling this "groundbreaking research", the fact the study involved rats was only mentioned once, halfway down the article, and even then, the Mail incorrectly reported that the researchers used mice.

 

What kind of research was this?

This was an animal study investigating the reward pathways in the brain that are involved when we eat sugar.

The researchers say previous studies where rats have been fed an excessive amount of sugary drinks have been shown to elevate levels of dopamine in an area of the brain called the nucleus accumbens. This is part of the mesolimbic pathway, often referred to as the reward pathway. Pleasurable activity such as eating food or taking particular drugs causes the release of the chemical dopamine in this pathway, which causes further desire for stimulus.

It is this pathway that is known to be involved in substance use and addiction. The rat studies have shown that when the excessive sugar is subsequently withdrawn, this causes a similar effect to that seen among people who are dependent on substances such as nicotine, alcohol or heroin.

This research aimed to see whether there could be a therapeutic target for reducing sugar consumption. Varenicline (brand name Champix) is a tablet licensed for smoking cessation. It works by binding to specific nicotinic acetylcholine receptors (α4β2). Normally, when nicotine activates these receptors, it reinforces the release of dopamine and associated behaviour.

Champix blocks these receptors, preventing the reinforcement and reward experienced with smoking. The study's aim was to see whether these drugs may also be effective in reducing sugar consumption.  

 

What did the research involve?

The study involved five-week old rats housed under standard conditions and given unlimited access to food and water. On about three days a week, they were also presented with another drinking bottle that contained 5% sugar solution. The researchers then started giving varenicline after short-term sugar exposure in one group of rats – four weeks on the sugar drinks – and after long-term sugar exposure in another group – 12 weeks. Varenicline was given by injection and the researchers tested different doses.

They also carried out different control scenarios. In one, another group of rats were given continuous exposure to sugar solution to look at voluntary consumption when it was available all the time, rather than intermittently. Instead of sugar, another group of rats were given saccharin solution three times a week, as per the standard protocol. This was to look at the effects of varenicline on consumption of a non-calorific sweetener.

The researchers also tested the effects of another drug called mecamylamine (not licensed in the UK) which binds to the receptors in a similar way.

The rats' weight, and volume of fluid consumed, were measured throughout. The brains of some rats were also examined after death.    

 

What were the basic results?

The researchers found that varenicline significantly reduced sugar consumption after both the short- and long-term intermittent sugar exposures. However, varenicline was only effective at the higher dose (2mg/kg) in the short-term group. In the long-term group, it was effective at both lower and higher doses (1 and 2mg/kg). The drug effect lasted for up to 30 minutes, but was no longer effective when the rats were assessed two and 24 hours after injection. 

Interestingly, varenicline also reduced consumption of saccharin solution. However, it was not effective in the rats with continuous access to sugar solution. Mecamylamine was similarly effective to varenicline at both 1 and 2mg/kg doses, and unlike varenicline was effective up to two hours after injection.

Examination of the rat brains also confirmed what the researchers had expected – that sugar consumption had been associated with increased binding at the nicotinic acetylcholine receptors in the nucleus accumbens, in a similar way to nicotine.

 

How did the researchers interpret the results?

The researchers conclude: "our results suggest that [nicotinic acetylcholine receptors] drugs such as varenicline may represent a novel treatment strategy for reducing sugar consumption." 
 

Conclusion

This animal research provides evidence that, as expected, the chemical reward pathways within brain – involving a region called the nucleus accumbens – are involved when excessive amounts of sugar are consumed on a regular basis. This is similar to that involved with substance addiction, such as nicotine. The researchers subsequently found evidence that the smoking cessation drug varenicline can reduce sugar consumption when injected into rats.

However, it is difficult to draw many further implications from the research at this stage. For one thing, we don't really know what type of dietary intake in humans this intermittent exposure to sugar solution in rats would be equivalent to. Also, the only evidence we have is that giving varenicline reduced sugar consumption in the immediate term for only 30 minutes after administration. After this, sugar consumption returned to previous levels. The drug would need to keep being given to be effective.

It seems highly unlikely that people would be given a varenicline tablet every day to stop them eating sugar. Such an approach on a population basis would be unfeasible and unsafe. Even for smoking cessation, the drug is normally only given for a maximum of 24 weeks.

The only theoretical implication it is possible to see at this stage, is that obese people who find it hard to stop eating sugar-laden foods and snacks could possibly be given varenicline in the short term to try and help them "quit".

However, this is only a speculation. The drug would first need to undergo testing in people to see if it was effective for excessive sugar consumption, if the benefits outweighed the risks of the drug, and whether it offered any advantage over other standard approaches to overweight and obesity, such as dietary control, physical activity and behavioural support.

There is also the issue of side effects. People who take varenicline often report feelings of irritability and anxiety, but it is hard to assess whether this is caused by the drug or is a result of nicotine withdrawal. It is unclear whether people taking varenicline because they had a "sweet tooth" would also experience similar side effects.

Overall, this is interesting research, but varenicline is still only licensed for smoking cessation in humans. Whether it may or may not have a future role in sugar addiction is unknown. What is known is that a healthy, balanced diet is currently the best way to reduce excessive sugar consumption and associated health risks of diabetes, overweight and obesity.   

Read more advice about how to reduce the amount of sugar you eat throughout the day.

Links To The Headlines

Anti-smoking drugs could stub out your sugar cravings: Common treatment that targets brain's 'reward pathways' may be used on people who are addicted to sugar. Daily Mail, April 11 2016

Links To Science

Shariff M, Quik M, Holgate J, et al. Neuronal Nicotinic Acetylcholine Receptor Modulators Reduce Sugar Intake. PLOS One. Published online March 30 2016

Categories: NHS Choices

Pregnancy diabetes screening should be 'performed earlier'

NHS Choices - Behind the Headlines - Fri, 08/04/2016 - 11:28

"Tests for diabetes in pregnancy – which affects the developing baby – are taking place too late," BBC News reports.

Screening often takes place during the 28th week, but a new study suggests that diabetes-related changes to the baby can occur before that time.

Diabetes that develops during pregnancy – known as gestational diabetes – is one of the most common complications of pregnancy, affecting around one in five women. It has been linked to various complications, such as the baby being large for its gestational age, which can cause problems during labour. Gestational diabetes can also increase the risk of stillbirth and miscarriages.

Due to the widespread nature of the condition, guidelines for England recommend that pregnant women are screened for it between the 24th and 28th week of their pregnancy.

Read about screening for gestational diabetes.

The study found that some babies of women with diabetes during pregnancy had already started to grow abnormally large for their age by the time the women were diagnosed at 28 weeks or later.

The authors expressed concern, as screening often takes place around the 28th week period, not the 24th.

The lead author of the study suggested that the lower estimate of current guidelines would be better to aim for.

The study didn't show whether any changes could be picked up at 24 weeks, so we don't know whether changes in the guidelines would improve outcomes. Other studies may be able to hone in on the optimum target age. 

Where did the story come from?

The study was carried out by researchers from The University of Cambridge and was funded by the National Institute for Health Research and the Stillbirth and Neonatal Death Charity.

Two of the authors disclosed potential conflicts of interest. One author has a patent submitted with the pharmaceutical company GlaxoSmithKline for the prevention of preterm birth. Another received support from GE Healthcare (another pharma company) in the form of the diagnostic ultrasound systems used for the study.

The study was published in the peer-reviewed medical journal Diabetes Care.

Both BBC News and ITV News reported the study accurately. The BBC usefully quoted Professor Gordon Smith, one of the researchers, who put the findings in context of current recommendations. He said: "The recommendations are that screening should take place at some point between 24 and 28 weeks, but in practice a lot screen at 28 weeks. Our findings indicate that it should be brought forward to 24 weeks and that would still be consistent with existing guidelines."

 

What kind of research was this?

This was a prospective cohort study looking at whether babies started growing larger before their mothers were diagnosed with diabetes in pregnancy – known as gestational diabetes.

Gestational diabetes is when there is too much glucose (sugar) in the blood of women during pregnancy (gestation). It affects about 18 in every 100 women giving birth in England and Wales. 

Gestational diabetes usually develops in the third trimester (after 28 weeks) and usually disappears after the baby is born. Most women with gestational diabetes have normal pregnancies and healthy babies. 

However, women who develop gestational diabetes are more likely to develop type 2 diabetes later in life. It also affects the unborn baby.

For example, the baby can grow larger than normal, causing problems during delivery, like raising the chance of caesarean section, premature birth, miscarriage or still birth. The baby itself is also more likely to be overweight or have diabetes later in life. 

 

What did the research involve?

The researchers tracked 4,069 first-time mothers-to-be and monitored their baby's growth rates in the womb.

Women were categorised into those with gestational diabetes diagnosed on or after 28 weeks (171, 4.2%) and a much larger group without gestational diabetes at all (3,898, 95.8%).

The main growth measure was the baby's waist circumference, estimated by ultrasound scans of the mum's womb at 20 and 28 weeks of pregnancy. They also measured head circumference and used a composite measure (head circumference to waist circumference ratio) as a second method of identifying babies with abnormal growth.   
 
The analysis adjusted for any slight inaccuracies in the duration of pregnancy, as it is not always easy to know your exact conception date, or estimate it looking back.

Baby growth at 20 and 28 weeks was divided into 10 groups, each representing 10% increments of growth. For example, a baby in the top 10%, sometimes called the 90th percentile, will be larger than 9 out of 10 other babies at this point in time. The researchers used these top 10% cut offs to identify babies that were larger than normal.

 

What were the basic results?

Of the 4,069 women, 171 (4.2%) had a diagnosis of gestational diabetes at or beyond 28 weeks.

At the 20-week scan, there were no differences in baby growth between those diagnosed with gestational diabetes and those without. However, the risk of having a large baby (head circumference and head-to-waist ratio) was higher in obese mothers.

At week 28, there were more pronounced differences.

Mothers diagnosed with gestational diabetes at 28 weeks or later were about twice as likely to have a large baby than those without, using head circumference as the main measure (relative risk [RR] 2.05, 95% confidence interval [CI] 1.37 to 3.07). The added risk using head-to-waist circumference ratio was about the same.

Obese mothers had a similar doubling in risk of larger babies.

Women who were obese and diagnosed with gestational diabetes at 28 weeks or later were around five times more likely to have a larger baby measured by head circumference (RR 4.52 5%; CI 2.98 to 6.85) and three times higher using head-to-waist circumference ratio (RR 2.80 9%; CI 1.64 to 4.78).

 

How did the researchers interpret the results?

The researchers concluded: "Diagnosis of GDM [gestational diabetes] is preceded by excessive growth of the fetal AC [abdominal circumference] between 20 and 28 wk gestational age, and its effects on fetal growth are additive with the effects of maternal obesity."

 

Conclusion

This cohort study suggests that babies of women diagnosed with gestational diabetes at 28 weeks or later may have already started to grow abnormally large for their age. Not every baby was affected, but the risk of a larger baby was higher in women who developed diabetes, and the changes had happened before they were diagnosed.

This increases the argument that screening for diabetes in pregnancy should be moved earlier than 28 weeks, although no differences were seen at 20 weeks, so this looked too early to be of any practical use.

Current recommended practice in England and Wales suggest women with gestational diabetes would usually be picked up at 24-28 weeks.  Although women with risk factors like obesity may be picked up much sooner. Those with a range of risk factors who book their first antenatal appointment in the first (up to week 12) or second trimester (up to week 27) are offered blood glucose self monitoring or a two-hour 75g oral glucose tolerance test to detect it. Women without these risk factors may be less likely to be detected until the 24-28 week window.

Prof Gordon Smith, one of the researchers, told BBC News: "The recommendations are that screening should take place at some point between 24 and 28 weeks, but in practice a lot screen at 28 weeks. Our findings indicate that it should be brought forward to 24 weeks and that would still be consistent with existing guidelines."

It is worth noting that the two groups of women were noticeably different at the start of the study. Women who went on to develop gestational diabetes were younger, shorter, more likely to be obese, gained less weight during pregnancy, and were more likely to have an induced labour or caesarean delivery.

This partly reinforces the approach of current guidelines, which aim to look at a range of risk factors in newly pregnant women to help identify mothers more likely to develop diabetes in pregnancy later on. Risk factors for gestational diabetes include:

  • BMI above 30kg/m2 – the obese category
  • previous large baby weighing 4.5kg or more
  • previous gestational diabetes
  • family history of diabetes (first-degree relative with diabetes)
  • minority ethnic family origin with a high prevalence of diabetes

While many of these risk factors are unavoidable, you can take steps to lower your BMI before trying for a baby.

Read more advice on lowering your weight while planning for a baby.  

Links To The Headlines

Pregnancy diabetes tests 'too late', warn scientists. BBC News, March 8 2016

Diabetes during pregnancy can put mothers at risk from 'abnormally large' babies, study shows. ITV News, March 8 2016

Links To Science

Sovio U, Murphy HR, Smith GCS. Accelerated Fetal Growth Prior to Diagnosis of Gestational Diabetes Mellitus: A Prospective Cohort Study of Nulliparous Women. Diabetes Care. Published online April 7 2016

Categories: NHS Choices

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