“Parents will receive text message and email advice on how to bring up their children after David Cameron said it was ‘ludicrous’ that people get more training in driving a car,” the Daily Mail has reported.

The story, covered in much of the media, is based on the launch of a new interactive service providing information and advice to parents.

 

Why is this in the news?

Launched today by the prime minister David Cameron, the NHS Information Service for Parents gives mums, dads and parents-to-be advice on issues around staying healthy in pregnancy, preparing for birth and looking after their baby. It includes:

• advice via email and text messages (SMS)
• short film clips of advice from midwives and parents
• online advice from the NHS

 

Why has this service been launched?

The three initiatives are reportedly being launched because of the impact a child’s care early in life has on their health, behaviour and ability to learn throughout their lives. A 2010 Department for Education survey of 2,319 parents of under-threes, found that 85% wanted practical help with caring for their baby.

 

What can mums and dads and parents-to-be expect from the service?

The free Information Service for Parents emails and texts contain NHS-approved advice and will be sent every week from five weeks pregnant through to four weeks after the birth of your baby. Fathers-to-be can sign up for advice specifically aimed at them. The email and text service is expected to offer more advice for parents of older children in the future.

The videos available from the Information Service for Parents demonstrate practical advice for parents and parents-to-be, including:

• how much weight should I put on during pregnancy?
• what’s involved in a caesarean section?
• how do I know if I have postnatal depression? 
• how can I get my baby to sleep?

There are already around 670,000 visits per month to the pregnancy and baby webpages on NHS Choices.

 

How can I sign up to this service?

Visit www.nhs.uk/parents to sign up to the service or find out more information. Alternatively, you can sign up at a midwife appointment or at pregnancy, child or parenting support organisations such as NCT, as well as a host of websites.

 

What else has been announced for parents today?

The NHS Information Service for Parents was announced alongside a trial of free parenting classes for all parents of children aged five years and under in:

• Middlesbrough
• High Peak (Derbyshire)
• Camden (London)

Mums and dads will be able to use vouchers to pay for the parenting classes, which are being offered by a large group of children’s and parenting charities. These parenting class vouchers are available from Boots stores, children’s centres and health visitors.

The government has also launched a trial of subsidised relationship support sessions to help expectant mothers and fathers, and those with children up to the age of two. These sessions are being offered in York, Leeds, North Essex, Hackney and City of London, by Relate, The Tavistock Centre for Couple Relationships and the Fatherhood Institute. The sessions are set to include help with:

• managing new roles and responsibilities in your relationship
• dealing with the emotional impact of having a child
• learning negotiating and compromising skills
• balancing your role as a parent and as a partner
• coping with issues such as lack of sleep and mess

Links To The Headlines

No 10 guide to changing nappies and baby talk. The Daily Telegraph, May 18 2012

No 10 scheme will text and email parents with child-rearing tips from choosing baby names to changing nappies. Daily Mail, May 18 2012

Marriage counselling for tired new parents. The Independent, May 18 2012

“Dieting in pregnancy is good for you,” according to The Independent, while the Daily Mail has warned pregnant women not to eat for two since “piling on the pounds during pregnancy” increases the risk of complications.

Both these news stories are based on a study that compared ways to manage weight during pregnancy, but did not tell women to diet or look at the effects of overeating, as the headlines implied. Instead, the research reviewed previous studies to look at how diet, exercise or a combination of the two affected maternal weight gain and the risk of health problems for babies. In particular, it found that compared to other interventions such as exercise, following a diet plan (not a weight-loss diet) during pregnancy was more effective at reducing the amount of weight mothers gained. This had no adverse effect on the baby and reduced the risk of pre-eclampsia, diabetes, high blood pressure and premature birth.

This large study comes in the wake of concerns about the growing problem of obesity in pregnancy, which can cause serious problems for the mother and is a risk factor for later obesity in the child. It has found that dieting during pregnancy to maintain a healthy weight is safe, effective and has no effect on the baby’s birth weight, a factor which many woman worry about.

Currently, pregnant women are advised not to “eat for two” or reduce their calories, but to follow a healthy, varied diet with plenty of fruit and vegetables and a minimal intake of foods that are high in fat and sugar. Women who suspect they are overweight or obese are advised to talk to a dietitian, who will help them with a weight management programme.

 

Where did the story come from?

The study was carried out by researchers from several institutions in Europe, including Queen Mary University of London and the University of Birmingham. It was funded by the National Institute for Health Research’s Health Technology Assessment Programme.

Predictably, many newspapers made a meal of reporting this research, warning women not to “eat for two” even though women have been advised against doing this for several years now. The Metro’s headline that expectant mothers were being “urged to go on a diet” was also misleading. The study did not advise all women to follow a calorie-controlled diet but instead suggested that dietary interventions should be targeted at women who are obese or overweight. The paper’s photo of a pregnant woman holding weights was also misleading, since the study found diet to be more effective than exercise at reducing weight in pregnancy.

 

What kind of research was this?

This meta-analysis combined the results of randomised controlled trials which had looked at the effects of diet, exercise or a combination of the two on weight gain in pregnancy. Researchers also explored whether such interventions had any other effects during pregnancy and birth, and whether they affected the weight of the baby.

The researchers point out that obesity is a “growing threat” to women of childbearing age, with half the population being either overweight or obese. In Europe and the US, 20–40% of women gain more than the recommended weight during pregnancy. The researchers say that excessive weight gain during pregnancy is associated with adverse pregnancy outcomes, while for the children maternal obesity is a risk factor for obesity during childhood, which can persist into adulthood.

The authors argue that there is a need to identify safe and effective ways to help women manage their weight during pregnancy.

 

What did the research involve?

The authors analysed the results of 44 randomised controlled trials involving over 7,000 women.

They conducted searches of several electronic databases to find trials on the subject of pregnancy and weight. They also searched for relevant unpublished studies in sources of information such as conference databases. From these, they selected randomised controlled trials that tested the effects of dietary or lifestyle interventions on maternal and baby weight, as well as maternal and foetal outcomes.

The interventions in the trials were classified into three groups: mainly diet-based, physical activity-based, or based on both diet and physical activity. Studies were assessed for the quality of their design and methods to minimise the risk of bias.

The main outcome assessed was weight-related changes in the mother and baby, but researchers also looked at whether diet or exercise were associated with the risk of other critical pregnancy outcomes, including gestational diabetes, pre-eclampsia (a dangerous complication of pregnancy), premature delivery, stillbirth and shoulder dystocia (an emergency during childbirth where one of the baby’s shoulders becomes stuck behind the mother’s pubic bone). They summarised the strength of the evidence for these outcomes using an established system for grading evidence.

To explore possible further adverse effects, they undertook a separate search and review of the safety of diet and exercise in pregnancy, based on established methods. They analysed the data from the selected trials using standard statistical methods.

 

What were the basic results?

The researchers’ analysis included 44 randomised controlled trials involving 7,278 women, looking at the effects of diet, exercise or a combination of the two.

The researchers compared the outomes seen in women who were assigned interventions and women in control groups (who were not offered any interventions). They found that:

• Women who dieted, exercised or did both gained on average 1.42kg less than women in the control groups (95% confidence interval [CI] 0.95 to 1.89kg).
• Dieting, exercising, or doing both had no significant effect on the baby’s birth weight (mean difference -50g, 95% CI -100 to 0g), or whether babies were large or small for gestation age (the amount of time they had spent in the womb).
• On its own, physical activity was associated with a reduced birth weight of 60g on average (95% CI -120 to -10g).
• Diet, exercise, or both reduced the risk of pre-eclampsia (relative risk [RR] 0.74, 95% CI 0.60 to 0.92) and shoulder dystocia (RR 0.39, 95% CI 0.22 to 0.70), with no significant effect on other critically important outcomes.
• Dietary intervention resulted in the largest reduction in mothers’ weight gain during pregnancy. Compared with controls, women following dietary interventions were 3.84kg lighter and had better pregnancy outcomes than with other interventions (95% CI 2.45 to 5.22kg).

The overall evidence rating for the underlying studies was reported as low to very low for important outcomes such as pre-eclampsia, gestational diabetes, gestational hypertension and preterm delivery.

 

How did the researchers interpret the results?

The researchers concluded that diet and exercise can reduce maternal weight gain and improve outcomes for both mother and baby, with dietary intervention being the most effective. The diets in the trials included:

• a conventional balanced diet (based on an energy intake of 18–24kJ per kg of body weight)
• a low-glycaemic diet with unprocessed whole grains, fruits, beans and vegetables
• a diet with a maximum of 30% fat, 15–20% protein and 50–55% carbohydrate

Based on their findings, the researchers suggest that regular advice on planned nutritional intake should be provided to woman from early pregnancy onwards, targeting overweight and obese women who they say would benefit most.

 

Conclusion

This study has found that dieting during pregnancy to maintain a healthy weight is safe, effective and has no consequential effect on the baby’s birth weight, a factor which many women worry about.

It’s important to correct some of the inaccurate news coverage of this research. The research highlights the importance of eating healthily during pregnancy, but does not mean that all pregnant women should be put on diets. Nor does it recommend a reversal of the current advice that women should not eat for two, which has long been discouraged.

While putting on too much weight can affect a woman’s health and increase the risk of complications, gaining too little weight can also cause problems and mean the body is not storing enough fat. The current advice is not to go on a weight-loss or calorie-restricted diet during pregnancy, although a woman’s midwife or GP may have special advice if she weighs more than 100kg. Instead, current advice is based on eating a balanced diet and managing weight at an appropriate level. While it’s unlikely to make juicy headlines, the simple fact is that women should eat a normal amount and a balanced range of nutrients.

Weight gain in pregnancy varies greatly, although most pregnant women can expect to gain 8–14kg, most of it after week 20, as the baby grows and the body lays down enough fat to make breast milk after the baby is born. The medical team supporting a woman during pregnancy will monitor her changes in weight and diet, and will make appropriate suggestions to help her and her baby be as healthy as possible.

Links To The Headlines

Pregnant women should not 'eat for two'. The Daily Telegraph, May 18 2012

Mums-to-be urged to go on a diet rather than 'eat for two'. Metro, May 18 2012

Now dieting in pregnancy is good for you. The Independent, May 18 2012

DON'T eat for two: Piling on the pounds during pregnancy increases risk of diabetes and high blood pressure. Daily Mail, May 18 2012

Links To Science

Thangaratinam S, Rogozińska E, Jolly K et al. Effects of interventions in pregnancy on maternal weight and obstetric outcomes: meta-analysis of randomised evidence. BMJ 2012; 344

“Good cholesterol” doesn’t lower heart attack risk, the Daily Mail has reported.

A great deal of research has previously suggested that higher levels of “good” HDL cholesterol reduce your risk coronary heart disease, while higher levels of “bad” LDL cholesterol increase your risk of a heart attack. However, it has been hard to tell whether HDL cholesterol directly reduces coronary heart disease risk as other medical, biological or lifestyle factors could be involved. To get round this, researchers have conducted a complex study identifying genes that raise levels HDL cholesterol, and then in turn looking at whether carrying these genes influences heart disease risk.

Researchers first identified genetic variants associated with high HDL levels and tested for them in several thousand people, including some who had had a heart attack. They found that carrying these ‘HDL cholesterol genes’ had no effect on the risk of a heart attack. From this, the researchers concluded that there is no direct relationship between HDL cholesterol and coronary heart disease, and therefore that other factors must be involved.

This is a complex study that challenges the commonly held belief that having higher HDL cholesterol will reduce heart attack risk. However, as it only looked at a particular set of genetic variations, it cannot provide the whole answer and tell us whether HDL cholesterol does or does not affect coronary heart disease, and how this effect might come about. An important question is whether things that increase HDL cholesterol levels during our lifetime (i.e. after our genetics are determined), such as exercise and certain medications, can then improve our heart disease risk.

 

Where did the story come from?

The study was carried out by researchers from Harvard Medical School and was funded by the US National Institutes of Health, Wellcome Trust, European Union, British Heart Foundation and German Federal Ministry of Education and Research. The study was published in the peer-reviewed medical journal The Lancet.

The media generally oversimplified what is a complex analysis. Also, captions referring to cholesterol intake through diet have no direct relevance to this research, which examined the genetic factors that determine HDL cholesterol levels and not the influence of dietary sources.

 

What kind of research was this?

There are two broad types of cholesterol in the body that are each associated with altered risk of cardiovascular problems: high-density lipoprotein (HDL) and low-density lipoprotein (LDL). LDL cholesterol is often referred to as “bad” cholesterol, as research has found that raised levels of LDL are associated with an increased risk of heart attacks. Conversely, previous observational studies have tended to show that people with higher levels of HDL (“good”) cholesterol have a lower risk of coronary heart disease (CHD).

However, it is difficult to prove that HDL cholesterol directly lowers people’s risk of CHD. For example, other factors in a person’s health and lifestyle might influence both HDL levels and CHD risk, so could be responsible for the apparent relationship between the two.

This study used a complex genetic analysis concept, called “mendelian randomisation analysis”, to investigate the relationship between genes, HDL cholesterol and CHD. Broadly speaking, Mendelian randomisation analysis looks at whether genetics that determine one factor (such as HDL cholesterol levels) are directly associated with the risk of an outcome (such as heart disease).

In this case, the researchers considered the theory that if increased HDL directly reduces CHD risk, then carriers of genetic variants that confer a high concentration of HDL cholesterol should have a reduced risk of CHD. If genetic determinants of HDL cholesterol had no relationship to CHD risk, then there isn’t a causal relationship between the two and other factors are likely to be involved.

This mendelian analysis has the important limitation that in looking at purely genetic factors, it does not look at how environmental, health and lifestyle factors then influence both HDL levels and CHD risk - basically, all the other things in our lifetime that occur after our genetics are determined at conception.

 

What did the research involve?

The researchers first identified a certain rare form of a gene called the endothelial lipase gene (LIPG Asn396Ser). This particular form of the gene, carried by about 2.6% of the population, was associated with levels of HDL cholesterol. Carriers of this gene variant had consistently higher levels of HDL (good) cholesterol compared to non-carriers, but no difference in their levels of LDL (bad) cholesterol or other blood fat levels. Based on the influence that carrying this LIPG variant had on HDL cholesterol levels, the researchers calculated that if the relationship between HDL cholesterol and CHD was causal, then they would expect carriers of this variant to have a 13% reduced risk of CHD.

To test whether carrying the gene variant had this great an effect, they used a case-control study that included 20,913 people who had had a heart attack (the cases) and 95,407 control participants. They examined whether, as they expected, carriers of the variant had around a 13% reduced risk of being among the cases and to have had a heart attack.

In another part of the study, they examined further gene variants in what they called a “genetic score”. They identified the 14 gene variants that were most commonly associated with HDL cholesterol levels, and the 13 gene variants that were most commonly associated with LDL cholesterol. They tested these variants in a further 12,482 cases who had had a heart attack and 41,331 controls.

 

What were the basic results?

Carriers of the LIPG genetic variant (Asn396Ser) had HDL cholesterol levels that were slightly higher than people who did not carry this gene (about 0.14mmol/L higher). However, while this led researchers to  expect that people carrying this variant would have around a 13% reduced odds of having had a heart attack, they found that carrying this variant had no significant effect on risk of a heart attack (odds ratio [OR] for heart attack 0.99, 95% confidence interval [CI] 0.88 to 1.11).

Following this phase, the researchers looked at a person’s carriage of up to 14 variants that were associated with higher HDL cholesterol levels. They once again found that an increased ‘HDL genetic score’ was not significantly associated with odds of having a heart attack. However, when they examined the LDL genetic score (based on a person’s carriage of up to 13 variants associated with higher LDL cholesterol levels), they found that this was associated with increased odds of having a heart attack (OR 2.13, 95% CI 1.69 to 2.69). In short, genetic variants that increased a person’s LDL cholesterol level were associated with higher CHD risk, as expected.

 

How did the researchers interpret the results?

The researchers concluded that certain genetic variants that raise blood HDL cholesterol do not seem to be related to the risk of heart attacks. They said that this data “challenges the concept” that raising HDL cholesterol levels will directly translate into reduced risk of a heart attack.

 

Conclusion

Previous research has tended to show that HDL cholesterol is “good” for you and higher levels reduce your risk coronary heart disease, while LDL cholesterol is “bad” for you and higher levels increase your risk of a heart attack. This complex research aimed to avoid the problem of the influence of other medical, biological or lifestyle influences by concentrating on genetics linked to HDL cholesterol and how closely they related to the risk of heart disease. If HDL cholesterol is directly related to CHD risk, then genes associated with high HDL levels should be directly associated with lower heart attack risk. Researchers carried out their study based on the theory that because our genetics are randomly assigned, participants can be considered to be randomly allocated to their circumstances and, therefore, equal.

However, the research did not find that HDL genetics determines the risk of heart disease. Instead, the gene variants that were associated with higher HDL cholesterol levels had no association with heart attack risk. This suggests that there may be no direct relationship between HDL cholesterol and coronary heart disease and, therefore, that other factors must be involved.

When the researchers examined gene variants that caused a person to have higher LDL (“bad”) cholesterol levels, they found that carriers of these variants were more likely to have had a heart attack than people without the variants. This would suggest that there is a direct causal relationship between LDL cholesterol and coronary heart disease, but not HDL cholesterol.

This is a complex study that challenges the commonly held belief that having higher HDL cholesterol will reduce heart attack risk. However, this study alone cannot provide the whole answer and tell us whether HDL cholesterol has any effect at all on coronary heart disease, and how this effect might be medicated. Also, only a few gene variants were examined and there may be many other genetic influences on HDL cholesterol and other blood fats.

Importantly, while our genetics are determined at conception, the environment that we live in for the remainder of our lives is likely to have an influence. Therefore, it is not possible to say how much our genetics influence our cholesterol compared with the many other risk factors for heart disease (such as diabetes and lifestyle factors including smoking, alcohol and exercise). Exercise in particular is thought to raise HDL levels during our lifetime, regardless of our genetic assignment at conception. This study cannot tell us how raising HDL cholesterol levels in adult life could influence coronary heart disease risk.

Analysis by Bazian

Links To The Headlines

'Good' cholesterol is not so great for you as study finds it doesn't lower heart attack risk. Daily Mail, May 18 2012

Eating 'good cholesterol' could be a waste of time. Metro, May 18 2012

Links To Science

Voight BF, Peloso GM, Orho-Melander M, et al. Plasma HDL cholesterol and risk of myocardial infarction: a mendelian randomisation study. Lancet. Published online May 17 2012

Everyone over the age of 50 should be given statins because the “cholesterol-busting” drugs reduce the risk of a heart attack even in healthy people, according to the Daily Telegraph and many other newspapers.

The story is based on a systematic review of 27 studies that looked at the effect of lowering “bad” cholesterol (low-density lipoprotein or LDL) using statin therapy in 175,000 people. It found that for every reduction in cholesterol of 1.0mmol/L, taking statins reduced the risk of heart attacks, strokes and other “major vascular events” by about a fifth (21%), even among people without vascular disease or who were at low risk of developing it.

Current guidelines recommend prescribing statins for people who have at least a 20% chance of developing cardiovascular disease within 10 years. Doctors normally calculate this risk by looking at a range of factors including the patient’s age, blood pressure, cholesterol levels, whether they smoke and whether they have diabetes.

This large review of studies suggests the cholesterol-lowering drugs are suitable for people who don't have heart or vascular disease and those who are not considered at high risk of developing it. The 21% reduction in risk of heart disease and stroke sounds impressive.

However, the number of people who stand to benefit from statins gets smaller as the risk threshold for treatment is reduced. For example, one thousand people at low risk would need to be treated (have a 1mmol/L reduction in bad cholesterol) for five years for 11 of them to benefit. This suggests that someone at low risk may wish to consider whether the possible benefit of taking statins would outweigh the inconvenience.

An editorial accompanying the review argues that the current guidelines should be revised so that age is used as an indicator for taking statins (over 50 years old), rather than using expensive screening tests. The commentary forms part of a running debate as to whether middle-aged people without any known risk of cardiovascular disease should be “medicated”, and, if so, how much (whether with statins, aspirin or a “polypill”, as previously suggested).

 

Where did the story come from?

The study was carried out by researchers from Oxford University and the University of Sydney. It was funded by several institutions including the British Heart Foundation, the UK Medical Research Council and Cancer Research UK. The study was published in the peer-reviewed medical journal The Lancet.

The study – in particular the commentary arguing for all over-50s to take statins – was covered widely and accurately in most of the media.

 

What kind of research was this?

This was a meta-analysis of individual patient data from 27 trials, which looked at the effects of lowering LDL cholesterol with statin therapy. It included trials of people without vascular disease or at low risk of cardiovascular disease.

The authors pointed out that their previous analysis of studies suggested that statin therapy to reduce LDL cholesterol in people without a history of vascular disease ultimately reduced their risk of heart attacks and strokes by about a fifth. However, uncertainty remains as to whether statins have an overall “net benefit” in this group, given that they are at low risk to begin with. The authors said that at least half of all heart attacks and strokes (vascular events) occur among individuals without previous disease.

The authors said they have now taken individual patient data from each trial within the database, allowing a more complete assessment of the effects of lowering LDL cholesterol in low-risk individuals.

 

What did the research involve?

The researchers conducted a meta-analysis of data from 175,000 participants in 27 randomised trials, to explore the effects of lowering LDL cholesterol with statin therapy. Trials were included if:

• they included at least one treatment where the main effect was to lower LDL cholesterol
• there were no other differences in treating risk factors
• at least 1,000 participants were recruited for a duration of at least two years’ treatment

The “major vascular events” the researchers looked at included heart attacks and deaths from heart attacks, strokes and coronary revascularisations (surgery to unblock coronary arteries). They also looked at rates of cancer and the cause of any death that occurred.

They grouped the participants into five categories depending on their risk of a vascular event within five years and compared those taking a statin with control groups or with group taking a lower-dose statin. The risk categories were:

• less than 5%
• 5% to less than 10%
• 10% to less than 20%
• 20% to less than 30%
• 30% or more

The researchers analysed the results using standard statistical methods.

 

What were the basic results?

The researchers found that:

• Reducing LDL cholesterol with a statin reduced the risk of major vascular events (relative risk [RR] 0.79, 95% confidence interval [CI] 0.77 to 0.81 per 1.0 mmol/L reduction), largely irrespective of age, sex, baseline LDL cholesterol or previous vascular disease, and of vascular mortality and all-cause mortality.
• The reduction in major vascular events was at least as big in people in the two lowest risk categories as those in the higher risk categories.
• For strokes, the reduction in risk in participants with a five-year risk of major vascular events lower than 10% (RR per 1.0 mmol/L LDL cholesterol reduction 0.76, 99% CI 0.61 to 0.95) was also similar to that seen in higher-risk categories.
• In participants without a history of vascular disease, statins reduced the risks of deaths from vascular disease and any other cause (RR 0.91, 95% CI 0.85 to 0.97).

There was no evidence that reducing LDL cholesterol with a statin increased cancer incidence, death from cancer, or deaths from other non-vascular causes.

 

How did the researchers interpret the results?

The researchers calculated that in people with a five-year risk of major vascular events lower than 10%, each 1mmol/L reduction in LDL cholesterol produced an absolute reduction in major vascular events of about 11 per 1,000 over five years. They said this benefit “greatly exceeds any known hazards of statin therapy”.

They also pointed out that, under present guidelines, such individuals would typically not be regarded as suitable for statin therapy.

They concluded: "The present report shows that statins are indeed both effective and safe for people with a five-year risk of major vascular events lower than 10% who would typically not be judged suitable for statin treatment … and, therefore, suggests that treatment guidelines might need to be reconsidered."

 

Conclusion

Current guidelines recommend statins for people who have a 20% or greater chance of developing cardiovascular disease within 10 years. This large review of studies, which further assessed previous research, suggests they may also benefit those without existing cardiovascular disease and those who are not considered at high risk of developing it.  However, the individual benefit for those at low risk may be small.

Although the study looked at whether statins increased the risk of cancer and death from other causes, it did not include possible adverse effects. Statins are safe drugs that have been associated with a small risk of side effects. As the authors stated, the risk of side effects when giving statins to everyone over the age of 50 would have to be taken into account when calculating the overall benefit.

Current guidelines on statin therapy from the National Institute for Health and Clinical Excellence (NICE) will reportedly be updated soon, at which point NICE will take this and any other new evidence into account.

There is good existing evidence that a healthy lifestyle (including regular exercise, stopping smoking and a healthy diet) are important factors in cardiovascular health. This study helps answer previous uncertainty about whether apparently healthy individuals could benefit from taking statins.

Links To The Headlines

Give statins to everyone over 50. Daily Express, May 17 2012

NHS 'should consider giving statins to healthy people'. BBC News, May 17 2012

Statins could benefit health of millions. The Guardian, May 17 2012

All over 50s should be taking statins. The Daily Telegraph, May 17 2012

Statins 'could benefit the healthy'. The Independent, May 17 2012

Why EVERYONE over 50 needs to be taking statins: Cholesterol-busting pills cut risk of heart attack or stroke. Daily Mail, May 17 2012

Links To Science

Cholesterol Treatment Trialists' Collaborators. The effects of lowering LDL cholesterol with statin therapy in people at low risk of vascular disease: meta-analysis of individual data from 27 randomised trials. The Lancet, May 17 2012 (published online)

The Daily Telegraph boldly and erroneously reports that “women really do have a 'gaydar' which allows them to tell someone's sexuality 'in the blink of an eye'”, while the Sun informs us that “most people have a ‘gaydar’”.

This story is based on a study that looked at how accurately people can judge someone’s sexual orientation from their face. In two experiments, researchers investigated how accurately US college students judged whether someone was ‘gay’ or ‘straight’ after quickly glancing at a photo. The research found that students were able correctly to determine sexual orientation slightly more often than could be put down to chance. It found that students were able to identify a woman’s sexuality correctly 65% of the time, and a man’s sexuality correctly 57% of the time. The research suggests that people may unconsciously make judgements about sexual orientation when seeing a face for the first time.

Based on this study, the headline that "most people have a gaydar" is misleading. Limited conclusions can be drawn from this small and highly artificial study as accuracy was only just better than chance. In order to draw firm conclusions, larger studies that include people of different ages and from different backgrounds are required. The type of study used does not consider the influence of other factors that could contribute to how a person makes quick decisions about another person’s sexuality and it is not clear whether quick judgements about a person’s sexuality occur in real life.

It is important to note that guessing another person’s sexuality may be a sensitive area. This study does not explore the consequences of making quick judgements about another person’s sexuality. It does show that a subjective snap judgement of someone’s sexuality based on their appearance has a good chance of being wrong. Making decisions on such snap judgements is ill advised, even if you think you have a great ‘gaydar’.

 

Where did the story come from?

The study was carried out by researchers from the University of Washington and Cornell University, US. It was funded by grants from the US Association for Psychological Science, Cornell University’s Einhorn Family Charitable Trust Endowment, the Cognitive Science Program, and the College of Arts and Sciences. The study was published in the peer-reviewed online journal Public Library of Science (PLoS) ONE.

This study was picked up by a variety of papers and online media and most had attention-grabbing headlines like “gaydar exists”. Apart from the overblown headlines, the Daily Mirror and the Sun reported the details of the study accurately. However, both The Daily Telegraph and Metro misleadingly suggest that the research showed women could judge another person’s sexuality better than men. In fact, the research showed that people were better able to judge whether women were gay or straight, not that women were better able to judge sexuality.

 

What kind of research was this?

This was an observational study that aimed to investigate how people make a judgement about someone’s sexuality based on their face. This was a relatively small study that only investigated the judgements of college students from one US university.

Previous research has indicated that there are two ways in which a person perceives a human face – “featural processing” and “configural processing”:

• featural processing involves looking at facial features such as the nose or eyes
• configural processing involves looking at the relationship between facial features, such as the distance between the eyes

 

What did the research involve?

Researchers undertook two experiments. In the first experiment, they recruited 24 University of Washington students (19 women) in exchange for extra course credits. The students viewed 96 photos of young adult men and women who identified themselves as gay or straight. The participants categorised each face as either straight or gay as quickly and accurately as possible. The photographs were of “white-looking” faces of people reportedly aged 18–29 gathered from Facebook. They included individuals living in 11 major US cities. Photographs were digitally altered to remove hairstyles so that only faces were visible. Faces with facial hair, make-up, glasses and piercings were excluded so as to limit any potential prejudice. Photos were flashed up on a screen for 50 milliseconds (approximately a third of the time it takes to blink the eye).

In the second experiment, comprising 129 students (92 women and 37 men), participants were randomly assigned to judge faces that were either upright or upside down. This experiment was designed to judge whether ability to read sexual orientation depends on configural processing (the relationship between features).

Results were analysed using statistical methods to determine whether the results were achieved by accurate judgement or whether similar results could have occurred by chance.

 

What were the basic results?

The main finding of this small study was that students were able to determine sexual orientation from glancing at a photo more often than could be put down to chance. (By chance alone it is assumed that people would be correct 50% of the time, like the toss of a coin.) It found that, in the first experiment students were able to identify the sexuality of women’s faces 65% of the time, while they were correct 57% of the time when viewing men’s faces. In the second experiment, the researchers found that when the picture was glanced at upside down, the success rate was less accurate (61% for women and 53% for men).

The researchers report that the increase in accuracy for judging upright faces suggests that the ability to read sexual orientation from men’s and women’s faces relies on configural face processing (relationships of facial features) as well as featural face processing (facial features). They say the results also indicate that reading sexual orientation from faces of women is easier than from faces of men.

 

How did the researchers interpret the results?

The researchers conclude that configural face processing significantly affects a person’s perception of sexual orientation and that sexual orientation is easier to detect in women’s faces than men’s faces.

The lead researcher, Joshua Tabak, is reported as having said that "we were surprised that participants were above-chance judging sexual orientation based on upside down photos flashed for just 50 milliseconds, about a third the time of an eyeblink". He went on to say that “people of older generations or cultures where homosexuality is not recognised may find it harder to make ‘gaydar’ judgments”.

 

Conclusion

This small study, carried out in highly artificial conditions, shows that students were able to judge sexuality with greater accuracy than could be put down to chance, and that women’s sexuality was judged more accurately than men’s sexuality. Despite these findings, the study should not be misinterpreted to mean that women are better at accurately judging a person's sexuality than men.

The participants' judgement was only just better than the results that could have been expected to have been achieved by chance and larger studies that include people of different ages and backgrounds are required to verify these results.

It is important to note that, in this study, students were instructed to make forced decisions about a person’s sexuality. It is unclear whether these quick decisions are made in real life situations. In addition, this study does not explore the consequences of making quick judgements about another person’s sexuality.

Guessing another person’s sexuality can be a sensitive area. This study highlights the importance of not making snap decisions based on your own subjective judgement of someone else’s sexuality because of the high chance that you may be wrong.

It is also worth noting the inaccurate reporting in both The Telegraph’s and Metro’s stories on this research. While the Mirror and the Sun also featured exaggerated headlines, their reporters did a better job of presenting the research.

Analysis by Bazian.

Links To The Headlines

Gaydar exists: we can tell who is gay and who is straight in the blink of an eye. Daily Mirror, May 18 2012

Gaydar quick as eye's blink. The Sun, May 18 2012

Study claims females really do have a 'gaydar'. Metro, May 18 2012

Women really do have a 'gaydar'. The Daily Telegraph, May 18 2012

Links To Science

Tabak JA, Zayas V. The Roles of Featural and Configural Face Processing in Snap Judgments of Sexual Orientation. PLoS One. Published online May 16 2012

“NHS ban on pill to treat prostate cancer is lifted,” the Daily Express has said, while the Daily Mail has warned that a “prostate cancer wonder drug” was set for approval “south of border but turned down by Scotland”. The stories focus on the fact that the prostate cancer drug abiraterone may soon be available on the NHS in certain circumstances.

These stories are based on a revised decision on draft guidance published by The National Institute for Health and Clinical Excellence (NICE), which makes recommendations about which treatments should be available on the NHS in England and Wales. It recommends that abiraterone (brand name Zytiga) be made available for the treatment of advanced prostate cancer that has not responded to chemotherapy.

Previous draft NICE guidance published in February rejected the use of abiraterone, concluding that it was not cost-effective. The new draft guidance has reconsidered this decision following an offer from the drug manufacturer to make the drug available at a lower price to the NHS.

The Scottish Medicines Consortium (SMC), which advises NHS bodies in Scotland about the status of new treatments, published guidance in March that rejected making abiraterone available. The SMC is currently considering further evidence and is due to publish further guidance this summer.

 

What is abiraterone used for?

Abiraterone is a type of hormone therapy for cancer that has spread beyond the prostate to other parts of the body (metastatic prostate cancer). It is a tablet taken once a day in combination with a steroid drug (prednisolone or prednisone), which reduces inflammation.

Hormone treatments for prostate cancer aim to block the production of certain male hormones (androgens) that stimulate prostate cancers to grow. Although there are already hormone treatments for prostate cancer, the new drug works in a different way by blocking cytochrome P17, an enzyme that enables the body to make androgens.

Abiraterone was licensed by the European Medicines Agency (EMA) in September 2011. After price changes made the drug more affordable, NICE guidance recommended abiraterone for use within certain circumstances. NICE said it is suitable is for men with:

• metastatic prostate cancer that has not responded to castration (either surgical where the testes are removed, or where medical treatments are used to block male hormones); and
• metastatic prostate cancer that has not responded to a chemotherapy regimen that contains docetaxel (a chemotherapy drug licensed for hormone-resistant prostate cancer)

NICE added that abiraterone should be used in combination with the anti-inflammatory drug predisnolone (or prednisone) in both these cases.

Alternative treatment options for men with metastatic prostate cancer, whose disease still progresses after treatment with docetaxel, include a drug called mitoxantrone, supportive care and re-treatment with docetaxel (which is not recommended in current NICE guidance).

 

How effective is it?

NICE has concluded that abiraterone is an effective second-line treatment for advanced (metastatic) prostate cancer.

Evidence for its effectiveness comes from a large randomised controlled trial carried out in 13 countries including the UK, from May 2008 to April 2009. The trial aimed to find out how well abiraterone worked for men who had already had other types of hormone therapy and chemotherapy for advanced prostate cancer.

One group of men in the trial took abiraterone once a day together with prednisolone, while the other group took a placebo plus prednisolone.

A primary analysis of the results showed that, on average, men who had abiraterone survived about four months longer than those in the placebo group (14.8 months compared with 10.9 months, hazard ratio 0.65, 95% confidence interval 0.54 to 0.77). The trial was stopped early once the benefits of the drug became clear.

The study also included analysis of a subgroup that had received one course of chemotherapy only (as opposed to more than one). It found that in this group, men who took abiraterone lived significantly longer than men who took the placebo (17.0 months compared to 11.7 months, hazard ratio 0.71, 95% confidence interval 0.60 to 0.86). NICE said that this group is likely to be treated with abiraterone in clinical practice and would have better treatment outcomes because they had less advanced disease.

Experts also told NICE that the most important benefits were extension to life and improved quality of life, including less pain and improved mental and physical health. NICE also concluded that the drug has the benefit of being in tablet form, which means patients can take it at home. It added that abiraterone is generally safe and any adverse reactions were tolerable.

 

Why was the drug previously turned down by NICE?

NICE had previously said that abiraterone should not be made available on the NHS because it was not cost-effective. NICE uses a measure called the quality-adjusted life year (QALY) to assess the value for money of a medical intervention. QALY is based on the number of years of life that would be added to a patient’s life, as well as the improvement in the quality of their life in that time added by any treatment. Each year of life is assigned a value.

NICE had previously said that although the drug had survival benefits, it did not feel the drug provided enough benefit to patients to justify the price the NHS was being asked to pay, even with an (undisclosed) discount on the list price then offered by the manufacturer, Janssen. It concluded that the most plausible cost per quality adjusted life year would be at least £63,000.

The list price of abiraterone is £2,930 for a 30-day supply of 120 tablets.

It also said that the drug did not meet its criteria for an end-of-life treatment as it did not consider the population for which the drug is licensed to be small.

 

What has changed now?

The manufacturer of abiraterone, Janssen, has offered the NHS a further undisclosed discount on the list price of the drug. Janssen also offered further information on which patients would benefit most (the subgroup who received only one course of chemotherapy), and clarified how many patients would receive the drug as an end-of-life treatment.

This has enabled NICE to conclude that the plausible cost per quality adjusted life year for this subgroup would be less than £50,000. In coming to this revised figure, NICE also took into account that abiraterone has other quality-of-life benefits, such as being an oral drug. It also meets the criteria for an end-of-life treatment which are:

• it would be used for men who would have a short life expectancy without treatment - less than 24 months 
• providing treatment would provide at least three months extension to life.

 

Is it definitely going to be made available?

NICE will now consult with interested parties on the new draft guidance recommending abiraterone, before it makes a final decision in June. Until then, NHS bodies are advised to make decisions locally on the funding of specific treatments.

Links To The Headlines

Prostate drug abiraterone 'set for NHS use'. BBC News, May 16 2012

England benefits from NHS postcode lottery at long last - as prostate cancer wonder drug looks set for approval south of border but not in Scotland. Daily Mail, May 16 2012

Prostate cancer: health watchdog reverses NHS guidance on drug. The Guardian, May 16 2012

Nice 'to reverse ban on prostate cancer drug'. The Daily Telegraph, May 16 2012

NHS ban on pill to treat prostate cancer is lifted. Daily Express, May 16 2012

         

Links To Science

NICE. Prostate cancer (metastatic, castration resistant) - abiraterone (following cytoxic therapy): final appraisal determination guidance. Published May 16 2012

Revolutionary surgery has given a paralysed man the ability to move his arms and hands again, it has been widely reported. The surgery, which made global news, has shown that rewiring nerves may allow surgeons to restore basic arm and hand control after serious spinal cord injuries.

A 71-year-old patient had been left paralysed from the neck down after the base of his neck was injured in a traffic accident. In a world first, surgeons were able to successfully bypass the injury site by grafting arm nerves from below the injury to nerves originating above the site of his injury. The surgery was given 23 months after his accident, and after several more months of therapy and training the man can handle objects, feed himself and even do basic writing.

This success story is clearly of massive significance to the man involved but also provides a blueprint for other surgeons around the country for how this technique may be applied in similar situations.

However, despite this fantastic success, it is important to bear in mind that this was an individual case, and it is not clear whether this technique will be equally successful in other patients with different types of spinal injuries or circumstances. The severity and location of the spinal cord injury are likely to be important factors in the success of this type of operation.

 

Where did the story come from?

The research was detailed in a report written by researchers from the Division of Plastic and Reconstructive Surgery and the Department of Neurological Surgery at Washington University School of Medicine in St Louis, Missouri in the US. The case report was published in the peer-reviewed Journal of Neurosurgery. The report did not specify any sources of funding for the research.

This story received widespread media coverage and many papers reported on the restoration of function in a previously paralysed man. The coverage of the story was generally well balanced and reflected the case report accurately.

 

What kind of research was this?

This case report described a surgical technique designed to restore nerve function to the arms and hands of a 71-year-old man who had been injured in a road traffic incident and left paralysed. The patient had experienced severing of the spinal cord at the top of his spine, causing him to be paralysed below the site of his injury. This meant the paralysis affected his arms and hands, as the nerves that control the arms are situated below the site of his spinal cord damage.

In this cutting-edge research surgeons created a 'nerve bypass' by grafting a working nerve originating in the spine above the injury site to the nerves in the lower arm originating below the injury site to restore some level of control lost following the injury.

Spinal cord injury (SCI) is devastating for the individuals affected and their families. Recovery from a complete SCI is rare, leaving most patients with significant permanent disability affecting the area below the site of the SCI. Despite advances in understanding the processes that occur in short- and long-term SCI, corresponding advances in surgical techniques or applications to repair them have so far lagged behind.

Case reports are often published that share interesting developments or new techniques in a particular medical field, in this case surgery. Case reports provide a detailed description of the background of a single person and the treatment they received, along with how effective the particular treatment course has been. They do not necessarily reflect what will be seen in all patients treated with the same techniques in the future, but still provide a good insight into new or experimental techniques.

 

What did the research involve?

The right-handed 71-year-old man presented to a surgical department 22 months after he was injured in a motor vehicle accident. He had sustained a spinal injury to the lower part of his neck, called the C7 vertebra. This caused extensive paralysis below the injury site. The strength and mobility of his limbs were extensively assessed to see if surgery might be able to help. Before surgery, he could flex his right wrist only weakly and could not pinch or grip with either hand. He could also not move his fingers on either hand.

A month after his initial assessment, the patient had surgery on both arms in a bid to restore some of the function of his hands. This was based on the concept that a working nerve originating in the spine above the injury site could be grafted onto the nerves in the lower arm to restore some of the control lost after the injury.  The 'nerve transfer' surgical technique involved taking a working nerve in the upper arm that originates from the C6 vertebral level (above the site of the injury), and joining it to the nerve system in the arm that originates from the C7 vertebra (the site of the injury).

This 'nerve rewiring' allowed working nerves above the spinal injury site to artificially connect with nerves below the injury site, which were previously unable to receive a signal due to the injury. Nerve transfer for spinal injuries is not new, but its application has so far been relatively limited.

After the surgery, the patient received continued hand physiotherapy to aid recovery and rehabilitation of the wasted hand muscles due to the injury.

 

What were the basic results?

During the operation, the surgeons stimulated the newly rewired nerves to check they were working and found that the nerve responses were essentially normal for the rewired nerves feeding the hand.

Eight months after the operation, the patient was able to move his left thumb and perform a pinching motion with his fingers and thumb in his left hand. The same increase in movement was achieved in the right hand after 10 months.

The authors report that he can now use his right hand to perform simple 'hand to mouth movements', and with his left hand he can feed himself and perform rudimentary writing activities. Recovery in the right hand has been slower than in the left.

Videos made available by the study group show that the man is now able to handle a ball with both hands, touch his fingers against his thumb in a pinching motion and feed himself. These were all activities he could not do before the surgery.

 

How did the researchers interpret the results?

The researchers said that, to their knowledge, this is the first reported case of restored nerve control of the thumb and finger flexing movement after a spinal cord injury.

They also said the patient’s 'function has improved significantly with his ability to feed himself'.

 

Conclusion

This case report represents the positive experience of a paralysed 71-year-old man who has been granted some manual control after a serious spinal injury to his neck. Before surgery, he could only make minimal arm movements controlled by the nerves above his injury site, but no lifting or fine hand movements as they are controlled by nerves joined lower down the spine, below the site of his injury.

While the nerve transfer technique given to this patient is not new, its application is not widespread and the authors say this is the first time it has been used to successfully rewire the nerves supplying a hand. Furthermore, these gains occurred after surgery that was carried out 23 months after the injury was sustained. This suggests that surgery does not have to be performed immediately, and that it may be possible to carry out the technique in people who have been paralysed for some time.

In addition to the hugely significant benefits to the man involved, this success story has also created a blueprint for other surgeons around the country for how this technique may be applied in similar cases.

However, it is important to bear in mind the limitations of the surgery and the evidence of its effectiveness. This case report represents the experience of just one individual. Therefore, it is not clear whether this technique will be equally successful in other patients with different types of injuries or circumstances. The severity and location of the spinal cord injury are likely to be important in determining the relative success of this type of operation. Also, the level of strength and control achieved in this case did not appear to represent a complete restoration of arm function, although it was clearly still a massive improvement.

Analysis by Bazian. Edited by NHS Choices.

Links To The Headlines

Prostate drug abiraterone 'set for NHS use'. BBC News, May 16 2012

For once England benefits from NHS divide as Nice set to approve prostate cancer drug turned down by Scotland. Daily Express, May 16 2012

Prostate cancer: health watchdog reverses NHS guidance on drug. The Guardian, May 16 2012

Prostate drug u-turn by NICE. The Daily Telegraph, May 16 2012

Nice 'to reverse ban on prostate cancer drug'. The Daily Telegraph, May 16 2012

NHS ban on pill to treat prostate cancer is lifted. Daily Express, May 16 2012

Links To Science

Mackinnon SE, Yee A, Ray WZ. Nerve transfers for the restoration of hand function after spinal cord injury. Journal of Neurosurgery, Published online May 15 2012.

New research has mapped the way that MRSA “superbug” bacteria spread, BBC News has reported. The results suggest that antibiotic-resistant bacteria may often spread from large, inner-city hospitals to smaller regional ones when patients are transferred.

The way that superbugs spread has been researched as part of an intricate study conducted by Scottish researchers, who looked at samples taken across the UK over 53 years. The researchers used genetic techniques to scan patterns and mutations within the various samples and to build up a “family tree” showing how a particular strain (called EMRSA-16) has spread between different hospitals across the country. They found that EMRSA-16 has generally spread by transmission from hospitals in large population centres in London and Glasgow to regional healthcare settings. The researchers suggested that patients’ referrals are an important cause of the spread of this bug across the country.

This type of study can provide useful estimates of transmission routes of MRSA, although there is still a need for further research incorporating a larger number of sampled hospitals to determine the wider UK pattern.

MRSA can be prevented through effective hand washing and screening before hospital admission. Find out more about preventing MRSA.

 

Where did the story come from?

The study was carried out by researchers from the University of Edinburgh and was funded by various research grants, as well as US governmental organisations including the National Institute of Allergy and Infectious Diseases, the National Institutes of Health and the Department of Health and Human Services. The study was published in the peer-reviewed journal Proceedings of the National Academy of Sciences USA (PNAS).

The story was covered accurately by BBC News.

 

What kind of research was this?

This study used genetic analysis of bacteria samples to map the way a particular form of MRSA spread between patients and hospitals across the UK. It collected information from infected patients in the UK over 53 years and looked at the emergence and transmission of EMRSA-16, a major clone (type) of MRSA. The study identified genetic elements and mutations of EMRSA-16 that allowed it to spread between patients and hospitals across the county.

MRSA (meticillin-resistant staphylococcus aureus) is a type of bacterial infection that is resistant to a number of widely used antibiotics. It is often referred to as a “superbug”. MRSA infections are more common in hospitals because patients often have an entry point, such as a surgical site, which allows the bacteria to enter the body. Also, bacteria can easily spread through direct contact with other patients and staff or contaminated surfaces.

Proper hand washing and screening are effective methods used to prevent MRSA infections from occurring. Rates of MRSA have fallen in recent years because of increased awareness of infection by both medical staff and the general public. However, it still places a considerable strain on the health system as it is more difficult to treat than other types of bacterial infection. Currently, all patients who go to hospital for a planned procedure are offered a swab test to see whether they are carrying MRSA bacteria.

 

What did the research involve?

Researchers looked at the genetic make-up of more than 80 variations of a major clone of MRSA called EMRSA-16 found in hospitals. Samples were collected from infected patients during a 53-year period. The EMRSA-16 clone of MRSA predominantly occurs in hospitals, and the researchers estimated that it has been present in UK hospitals for about 35 years. Researchers then identified genetic elements and mutations in the bug and tracked how these spread between patients and hospitals across the country.

Researchers used a specialist approach to map part of the genetic make-up of each sample, looking for changes and patterns in its genetics. In effect, this allowed them to build up a “family tree” showing how different strains had developed.

 

What were the basic results?

The key finding of this study was that EMRSA-16 has spread within the UK by transmission from central hospitals serving large populations to smaller, regional healthcare settings. It found that Glasgow in west Scotland was a hub for transmission to 16 surrounding regions in the north and east of Scotland. Similarly, in London EMRSA-16 spread from large city hospitals to smaller surrounding hospitals in south and southeast England.

 

How did the researchers interpret the results?

Study lead Dr Ross Fitzgerald reported that “our findings suggest the referral of patients to different hospitals is a major cause of MRSA transmission around the country.” He also said that “variants of MRSA circulating in regional hospitals probably originated in large city hospitals.”

The researchers concluded that these findings could help prevent the spread of drug-resistant infections such as MRSA.

 

Conclusion

This study estimates how a strain of MRSA (EMRSA-16) may spread from hospitals in major UK cities to smaller regional healthcare settings. Findings from this study are supported by findings of a recent US study, which estimated high transmission routes from large hospitals to long-term care facilities.

The researchers note that the dataset used is limited by the relatively small number of hospitals sampled. Despite its interesting findings, further research is required that incorporates a larger number of sampled hospitals to determine the pattern of spread elsewhere in the UK.

Collecting data on the prevalence and spread of superbugs such as MRSA (medically known as surveillance) plays an important role in containing and eradicating potentially harmful bacteria in medical settings, and ultimately reducing the number and severity of hospital-acquired infections. When used strategically, data of this type, along with simple but effective measures such as thorough hand washing, can make a difference to the spread of infections, as illustrated by the recent fall in MRSA in NHS hospitals.

Analysis by Bazian

Links To The Headlines

Large city hospitals 'breed and spread' MRSA. BBC News, May 15 2012

MRSA outbreaks start at major city hospitals. Daily Express, May 15 2012

Links To Science

McAdam PR, Templeton KE, Edwards GF et al. Molecular tracing of the emergence, adaptation, and transmission of hospital-associated methicillin-resistant Staphylococcus aureus. PNAS, Published online before print May 14 2012

“Overweight mothers-to-be could be condemning their unborn children to decades of ill health,” the Daily Mail reported.

The news is based on the results of large, long-term research that examined mothers’ body mass index (BMI) before and during pregnancy and how this was linked to various indicators of their children’s health when their children reached 32 years of age. These indicators included BMI, waist size and levels of fat and sugar in the blood, which are associated with the risk of conditions such as diabetes and heart disease.

Researchers found that higher maternal BMI before pregnancy was associated with increased BMI in children, as well as larger waistlines, raised blood pressure and increased blood levels of insulin and fat. Greater maternal weight gain during pregnancy was also associated with increased BMI, waist size and levels of fat in the blood.

This study adds to a growing body of evidence that mothers’ weight before and during pregnancy may affect a range of health-related factors in their children, perhaps even in the long-term. That said, this study’s design means that on its own it cannot prove that a mother’s weight or weight gain during pregnancy are responsible for the health effects seen in their grown-up children. For example, many complex environmental, social and genetic influences are known to determine who develops obesity.

Although the long-term effects of maternal weight are unclear from this study, excess weight is known to increase the risk of complications during birth, as well as making it harder to conceive in the first place. This study highlights the importance of maintaining a healthy weight for these reasons, rather than the potential long-term ones.

The Daily Mail also reported that “concern about the issue is so high that British doctors have started to medicate babies in the womb.” The newspaper appears to be referring to ongoing research into treating women for high blood sugar during pregnancy. This valuable study primarily aims to treat mothers, rather than their unborn babies, to cut potentially dangerous complications, rather than to improve their children’s long-term health.

 

Where did the story come from?

The study was carried out by researchers from the Hebrew University-Hadassah in Israel and the University of Washington in the US. It was funded by the US National Institutes of Health and the Israeli Science Foundation. The study was published in the peer-reviewed medical journal Circulation.

The story was accurately covered by the Daily Mail. However, it should be noted that this study measured factors that can contribute to various diseases, but did not determine the rates of negative health outcomes such as heart attacks, diabetes and strokes mentioned in the news coverage.

 

What kind of research was this?

This cohort study examined how mothers’ BMI and weight changes during pregnancy were associated with various markers of disease in their children once they reached adulthood. The disease markers of interest were waist circumference, BMI, blood pressure and levels of glucose, insulin, fats and lipoproteins in the blood. These were measured once the children reached 32 years of age. Maternal BMI and weight changes during pregnancy were reported by mothers in interviews conducted by nurses while they were in hospital after having their baby.

This is the ideal study design to examine a possible association between maternal weight and children’s health. The study’s strengths also included its large size and long follow-up. However, this type of study can only find associations between factors, and cannot prove a cause-and-effect link. This is because researchers cannot exclude the possibility that another factor is responsible for the association seen.

 

What did the research involve?

This research drew on data from a large, long-running study called the Jerusalem Perinatal Study. The research collected the following information on births in Jerusalem between 1974 and 1976:

• demographic and socioeconomic information
• medical conditions of the mother during current and previous pregnancies and gynaecological history
• smoking status of the mother
• height, pre-pregnancy weight and end-of-pregnancy weight of the mother
• child’s birth weight and gestational age

This information was obtained from maternity ward logbooks, birth certificates and interviews with mothers while they were hospitalised after having their baby.

In this study, a sample of 1,400 individuals born during this period was interviewed and examined again between 2007 and 2009 (when they reached 32 years of age). Individuals who had been born as part of a multiple birth, who were premature or who had congenital malformations were excluded. The researchers collected data on:

• height
• body weight
• waist circumference
• blood pressure
• levels of glucose, insulin and fats in the blood

The researchers looked at associations between maternal pre-pregnancy BMI and weight gain during pregnancy and children’s outcomes at 32 years of age. During their calculations, they accounted for gender, ethnicity and other factors that could explain any relationship seen, including:

• how many previous pregnancies a mother had had
• the mother’s age at the birth
• maternal smoking, and smoking status of the children as adults
• socioeconomic status
• maternal education, and education of the children
• maternal medical condition
• the children’s birth weight and gestational age
• physical activity of the children 

 

What were the basic results?

The researchers found that greater maternal BMI before pregnancy was associated with the following factors in grown-up children at the age of 32:

• increased BMI
• increased waist circumference
• increased blood pressure
• increased blood levels of insulin and fat 
• lower levels of high-density lipoprotein cholesterol

These associations were independent of weight gain during pregnancy (i.e. were evident regardless of how much weight a mother gained during pregnancy).

Greater weight gain during pregnancy was associated with:

• increased BMI
• increased waist circumference
• increased blood levels of fat 

When calculating these various associations, the researchers split mothers into four evenly sized groups, based on their pre-pregnancy BMI. They found that, on average, the adult children of women in the group with the greatest BMI (maternal BMI more than 26.4kg/m2) went on to have a BMI of  five units (kg/m2) higher than the children of mothers in the lowest quarter (maternal BMI less than 21.0kg/m2).

 

How did the researchers interpret the results?

The researchers concluded that “maternal size both before and during pregnancy is associated with cardiometabolic risk factors in young adult offspring.”  In other words, mothers who have a high BMI before pregnancy or who gain a lot of weight during pregnancy are more likely to have children who have risk factors for various metabolic and heart-related health problems in adulthood.

The researchers added that these associations appear to be driven mainly by children’s body fat during adulthood.

 

Conclusion

The link between pregnant women’s weight and the health of their children has been in the public eye several times in recent months, with high-profile news stories questioning whether our mothers can “programme us to be fat” and the need to “treat babies for obesity while still in the womb”.

This latest study analysed potential links between mothers’ excess weight around the time of pregnancy and “cardiometabolic risk factors” in their children decades later. Cardiometabolic risk factors are factors such as raised BMI and blood sugar, which signal that a person has a higher risk of conditions such as diabetes and heart disease.

The study found a long-term relationship, with higher maternal weight (assessed using BMI) and greater weight gain during pregnancy associated with a number of factors in the mothers' children at the age of 32. These included increased BMI, waist circumference, blood pressure and blood levels of insulin and fats, and decreased levels of high-density lipoproteins (“good cholesterol”) in children. As the authors state, this study “adds to and extends accumulating evidence” of this relationship, as similar findings have been reported in other studies.

This study has shown associations between maternal weight and children’s later health, but it cannot show cause and effect. This is because it cannot rule out the possibility that another factor is responsible for the association seen. Also, both pre-pregnancy weight and weight gain were not directly measured but were reported by mothers in interviews conducted by nurses after delivery. This may have led to some inaccuracy in the calculation of BMI and makes the results less reliable.

The average pre-pregnancy BMI of women in this study was 24kg/m2 (within the healthy range) in mid-1970s Jerusalem. This population may not be typical of pregnant women in the UK today.

In addition, the exact mechanism by which maternal pre-pregnancy weight and weight gain during pregnancy might cause increased levels of cardiometabolic risk factors in children remains to be determined. Several mechanisms, including shared genetic and environmental characteristics or changes caused by exposures in the womb, have been proposed, although none is completely clear.

Analysis by Bazian

Links To The Headlines

Obesity legacy of mums-to-be: Carrying too many pounds in pregnancy can give your baby a life of weight problems. Daily Mail, May 15 2012

Links To Science

Hochner H, Friedlander Y, Calderon-Margalit R et al. Associations of maternal prepregnancy body mass index and gestational weight gain with adult offspring cardiometabolic risk factors/clinical perspective : The Jerusalem perinatal family follow-up study. Circulation, February 17 2012, 2012;125:1381-1389 (published online before print)

Women concerned about PIP breast implants can find all the latest NHS information about the issue in our Health A-Z section on PIP implants.

Worries about the implants have emerged since news of a major investigation into them in France was widely covered in the media in December 2011.

Initially it was thought that around 40,000 women in the UK had the implants but on March 15 the Department of Health said new evidence meant a further 7,000 women in the UK might have them. About 95% of the implants were provided privately for purely cosmetic reasons.

The French implants caused global concern after it was revealed they contained industrial silicone rather than medical-grade fillers and that they may be more prone to rupture and leakage than other implants.

Initially reports also linked the implants to a rare form of cancer known as ALCL. This cancer link has been now been firmly discounted by medical experts here and in Europe.

 

What type of implants are involved?

The implants involved are called Poly Implant Prosthèse (PIP) and were made by a French company of the same name.

In a Medical Device Alert in March 2010, the Medical and Healthcare products Regulatory Agency (MHRA) said: " ... most
breast implants manufactured by the company since 2001 have been filled with a silicone gel with a composition different from that approved".

That alert was based on advice from French regulators. However, after an investigation by the MHRA, the French authorities reported in March 2012 that PIP implants made before 2001 may also contain unauthorised silicone gel.

PIP gained approval to market its silicone implants in 1997 but it is not clear when it began using a cheap type of silicone gel intended for making mattresses.

The marketing, distribution and use of the PIP implants was suspended in March 2010.

 

Do the implants have to be removed early?

About one breast implant in five needs replacing within 10 years, whatever the make, so it is unlikely that all the 7,000 women who had PIP implants before 2001 still have the same implants.

An expert committee was set up recently to examine the specific risks associated with PIP implants. It concluded that there was not enough evidence to recommend their early removal. That advice has not changed. For more details, read the expert review group's report (PDF, 159kb).

Links To The Headlines

No Routine Removal For PIP Breast Implants. Sky News, January 6 2012

NHS will remove implants free of charge for their patients but private clinics must pay for operations themselves, Government says. Daily Mail, January 6 2012

Government will pay for women who had breast implants on NHS to have them removed. The Daily Telegraph, January 6 2012

Clinics 'should remove implants'. BBC News, January 6 2012