June 2010: Heart disease risk high in women with PCOS and diabetes

Women with PCOS who have the metabolic syndrome and/or type 2 diabetes are at a very high risk of cardiovascular (heart and blood vessel) disease according to a new consensus statement from the Androgen Excess and Polycystic Ovary Syndrome (AE-PCOS) Society.

The society established a panel to review the current evidence of cardiovascular risk in PCOS and provide recommendations. Based on their findings they made the following conclusions and recommendations:

Women with PCOS who are obese, who smoke, who have abnormal blood fats or blood pressure or who have impaired glucose tolerance (pre-diabetes) are at risk of cardiovascular disease
Women with PCOS who have themetabolic syndrome and/or type 2 diabetes mellitus are at highrisk for cardiovascular disease
All women with PCOS should have measurements of their body mass index (based on weight and height), waist circumference, blood fats, blood glucose levels and blood pressure
Women with PCOS who are obese, older or who have a history of gestational diabetesor family history of type 2 diabetes should have an oral glucose tolerance test to check for diabetes
All women with PCOS should be assessed for mood disorders including depression.
Lifestyle managementis recommended for women with PCOS to reduce the risk of cardiovascular disease and should aim to improve blood fats – this should include an initial aim of 5-10% weight loss, with a longer-term goal of 10-20% weight loss and maintenance. If risk factors persist after lifestyle changes, insulin-sensitising medications (such as the diabetes medication metformin) and blood pressure and cholesterol-lowering medications should be added.

Polycystic Ovary Syndrome (PCOS) is one of the most common endocrine disorders in women, affecting an estimated 5-10% of women of reproductive age. Women with this condition suffer from irregular periods, infertility and symptoms of excess male hormones such as acne and excess hair growth. It is now known that the majority of women with PCOS have insulin resistance as the underlying cause of their PCOS – insulin resistance is an insensitivity of the muscles and cells to insulin and is the same problem that occurs in type 2 diabetes. Many women with PCOS therefore also have type 2 diabetes or are at risk.

Wild et al. Assessment of Cardiovascular Risk and Prevention of Cardiovascular Disease in Women with the Polycystic Ovary Syndrome: A Consensus Statement by the Androgen Excess and Polycystic Ovary Syndrome (AE-PCOS) Society. The Journal of Clinical Endocrinology & Metabolism Vol. 95, No. 5 2038-2049.

April 2010: Breastfeeding protects against type 2 diabetes

A new Australian study has found that women who breastfeed have a significantly lower risk of developing type 2 diabetes.

Researchers from the University of Western Sydney and colleagues studied the effect of both childbearing and breastfeeding on a women’s subsequent risk of developing type 2 diabetes. They studied close to 53 000 women, collecting information on pregnancies, breastfeeding and diabetes diagnosis.

Their findings were published online ahead of print in Diabetes Care on March 23^rd showing that 6% of the women had type 2 diabetes and overall the risk was similar in those who had children and those who didn’t. However among those who had children, the women who had breastfed had a much lower risk of developing type 2 diabetes – they estimated that every year of breastfeeding reduced diabetes risk by about 14%. The researchers also found that compared to women who hadn’t been pregnant, those who had children and who didn’t breastfeed had almost a 50% increased risk of developing diabetes, while those who breastfed for at least 3 months with each child were not at significantly greater risk.

Liu et al. Parity, breastfeeding and the subsequent risk of maternal type 2 diabetes. Published online before print March 23, 2010, doi: 10.2337/dc10-0347

March 2010: Prediction of future diabetes in women with gestational diabetes

Having higher blood glucose levels during pregnancy and a family history of diabetes increases the risk of a woman with gestational diabetes developing type 2 diabetes in the future according to a new study.

It is well known that women with gestational diabetes (diabetes in pregnancy) have a higher risk of developing type 2 diabetes later in life. But not all women go on to develop diabetes so researchers from Lund University in Sweden set out to determine if certain factors could help to predict which women might be more likely to end up with diabetes.

They studied 174 women with gestational diabetes, who had an oral glucose tolerance test during pregnancy and 1, 2 and 5 years after having their baby. They then compared measures of blood glucose control and insulin sensitivity in women who developed abnormal glucose levels compared to those whose glucose levels remained normal.

The researchers found that after 5 years, almost one-third of women had developed diabetes and more than half had some form of abnormal glucose tolerance (ie impaired glucose tolerance, impaired fasting glucose or diabetes). Fasting glucose and HbA1c (a measure of average glucose levels over the past 2-3 months) levels during pregnancy were higher in women who developed diabetes compared to those whose glucose levels remained normal. In fact having an HbA1c of 5.7% or more and a fasting glucose level of 5.2mmol/L or higher increased the chances of developing diabetes four-to-six fold. The researchers also report that having a family history of diabetes or having a greater number of previous pregnancies increased the risk of developing diabetes.

Ekelund et al. Prediction of postpartum diabetes in women with gestational diabetes mellitus. Diabetologia 2010; 53 (3): 452-457.

February 2010: Work & finance-related stress leads to metabolic syndrome

Stressful life events, particularly work and finance-related, may increase the risk of the metabolic syndrome according to a new Finnish study. The metabolic syndrome, also known as syndrome X or the insulin resistance syndrome, is a collection of symptoms (including raised blood glucose levels, blood fats, blood pressure and carrying weight around the middle) which occur together and can increase the risk of type 2 diabetes, heart disease and stroke.

Researchers from the University of Helsinki in Finland studied more than 3400 men and women aged 18 to 78 years who were part of a large, population-based study. They were asked to rate the severity of 15 different stressful life events related to finance, work, social relationships, health and housing.

In comparison with those who didn’t report any extremely stressful life events, those who reported work or finance-related stressful events were significantly more likely to have the metabolic syndrome. This risk was increased further, the more stressful events a person experienced in any of the areas assessed.

The researchers also found that the accumulation of stressful life events was associated with individual components of the metabolic syndrome including insulin resistance, obesity and high triglycerides (blood fats). These findings remained after adjusting for sex, age, lifestyle or family history of diabetes.

While we all know that diet and exercise are important for metabolic health, this study highlights the importance of reducing or managing stress in addition to other lifestyle changes.

Pyykkönen et al. Stressful Life Events and the Metabolic Syndrome: The Prevalence, Prediction and Prevention of Diabetes (PPP)-Botnia Study. Diabetes Care 2010; 33:378-384 .

February 2010: Sleep quality and quantity predicts diabetes risk

Both the quality and quantity of sleep you get can influence your risk of type 2 diabetes, according to the new review of the research in this area.

The authors reviewed all studies published in the topic of sleep and diabetes risk between 1955 and 2009. They found that both the quality and quantity of sleep predicted diabetes risk. More specifically, that:

· Sleeping 5-6 hours per night or less increased the risk of type 2 diabetes by 28%

· Sleeping more than 8-9 hours per night increased the risk by almost 50%

· Having difficulty getting to sleep increased the risk by 57%

· Having trouble staying asleep increased the risk by 84%

The authors suggest that the underlying mechanisms may differ between short and long sleepers, but nonetheless these findings highlight the importance of getting the right amount of good quality sleep when it comes to preventing diabetes.

Cappuccio Quantity and Quality of Sleep and Incidence of Type 2 Diabetes: A systematic review and meta-analysis. Diabetes Care February 2010 vol. 33 no. 2 414-420

February 2010: Dietary fibre prevents weight gain around middle

Eating more dietary fibre may help prevent weight gain and an expanding waistline according to a new study.

Researchers from the National Institute for Public Health and the Environment in Bilthoven, the Netherlands set out to look at the relationship between total dietary fibre, cereal fibre, and fruit and vegetable fibre with changes in weight and waist circumference. They studied more than 89 400 participants from 5 different European countries. They were aged 20 to 78 years and free of cancer, heart disease and diabetes when the study began. Dietary information was collected using food-frequency questionnaires which were specific to the eating habits of each country, and the participants were then followed up for an average of 6.5 years.

After adjustment for follow-up duration; other dietary variables; and baseline anthropometric, demographic, and lifestyle factors there was an inverse association between fibre intake and subsequent changes in weight and waist circumference. In other words, those who ate more fibre were less likely to gain weight, particularly around their waist.

The researchers suggest that while individual effects may be small, these changes could be of public health significance, estimating that a 10g increase in dietary fibre intake would prevent approximately 10% of average weight gain. This increase in fibre could be achieved by switching 2 slices of white bread to grain bread, 1 cup of white pasta to wholemeal pasta and snacking on a small handful of almonds in place of other low fibre snacks.

Du et al. Dietary fiber and subsequent changes in body weight and waist circumference in European men and women. Am J Clin Nutr 2010 Feb;91(2):329-36.

January 2010: Eating slowly improves satiety

The idea that eating quickly may lead to weight gain is not an old wives’ tale according to researchers from the Athens University Medical School in Greece, who have found that eating at a more moderate pace results in a greater production of satiety hormones than eating quickly.

The researchers asked 17 healthy volunteers to consume the same test meal (300ml of ice-cream) on 2 occasions – on one occasion they had to eat the meal in 5 minutes and on the other occasion they were asked to take 30 minutes to finish the meal. In the 3 hours following the meal, measurements were taken of hormones which affect hunger and fullness. The participants were also asked to rate their feeling of hunger and fullness using visual analog scales.

The researchers found that eating slowly resulted in a greater production of satiety hormones than eating quickly. The participants also rated their fullness as being higher immediately following the 30-minute meal compared to the 5-minute meal. Similar results were seen in normal weight and overweight participants.

The researchers conclude that ‘the warming we were given as children that wolfing down your food will make you fat may in fact have a physiological explanation’.

Kokkinos et al. Eating slowly increases the postprandial response of the anorexigenic gut hormones, peptide YY and glucagon-like peptide-1. J Clin Endocrinol Metab. 2010; 95 (1):1-5.

December 2009: Breastfeeding for longer reduces metabolic risks for mum

Breastfeeding is not only good for the newborn baby but may also reduce a mothers long term health risks, particularly for women who had gestational diabetes during their pregnancy.

Researchers from the University of Minnesota and colleagues studied almost 1400 women who were part of the Coronary Artery Risk Development in Young Adults (CARDIA) Study, an ongoing observational study in the US. Women who had not previously given birth and did not have the metabolic syndrome when the study began were followed up after 7, 10, 15 and/or 20 years.

Of the 704 women who gave birth (84 of whom had gestational diabetes, GDM), 120 developed the metabolic syndrome at follow-up. Women with GDM were twice as likely to develop the metabolic syndrome compared to women without GDM. Breastfeeding for a longer period of time was associated with a lower incidence of the metabolic syndrome and this risk reduction was found to be stronger in women with GDM.

The researchers conclude that breastfeeding may have persistent favorable effects on women's cardiometabolic health, particularly for women with a history of gestational diabetes.

Gunderson et al. Duration of Lactation and Incidence of the Metabolic Syndrome in Women of Reproductive Age According to Gestational Diabetes Mellitus Status: A 20-Year Prospective Study in CARDIA—The Coronary Artery Risk Development in Young Adults Study. Published online before print December 3, 2009, doi: 10.2337/db09-1197

December 2009: Family history predicts gestational diabetes risk

Women who have a sibling with diabetes are more than 7 times as likely to develop gestational diabetes (diabetes during pregnancy) than those without a family history according to a new study. This risk is higher than for women who have parents with diabetes.

Researchers from the University of Michigan Medical School in the US and colleagues studied more than 4500 women taking part in the National Health and Nutrition Examination Survey III (NHANES III) who had previously given birth. They were asked about their family history of diabetes and were classified as having a history of gestational diabetes, diagnosed diabetes or neither.

After adjusting for age and race, compared to women with no family history of diabetes:

· Women who had a mother with diabetes had 3 times the risk of developing GDM

· Women who had a father with diabetes had more than 3 times the risk of developing GDM

· Women who had s sibling with diabetes had more than 7 times the risk of developing GDM

Interestingly, a different pattern was seen for risk of type 2 diabetes, where a parental history increased the risk to a greater extent than having a sibling with diabetes – in fact having both parents with diabetes increased the risk of developing type 2 diabetes around eight-fold.

The researchers suggest that gestational diabetes may follow a different pattern of inheritance than type 2 diabetes and conclude that further investigation of these patterns could help identify women who are at particularly high risk of developing type 2 diabetes after having gestational diabetes.

Kim C, Liu T, Valdez R, et al. Does frank diabetes in first-degree relatives of a pregnant woman affect the likelihood of her developing gestational diabetes mellitus or nongestational diabetes? Am J Obstet Gynecol 2009;201:576.e1-6

November 2009: Male relatives of women with PCOS at risk for Metabolic Syndrome

There is a high prevalence of metabolic syndrome in fathers and brothers of women with polycystic ovary syndrome (PCOS), according to researchers from the Boston University School of Medicine.

Women with PCOS have been found to have twice the risk of the metabolic syndrome compared to the general population, and the risk is also higher in their mothers and sisters. In this study the researchers studied more than 200 fathers and almost 60 brothers of women with PCOS, comparing them to more than 1600 subjects of similar age and race, taking part in a large national study.

The metabolic syndrome, also known as syndrome X or the insulin resistance syndrome, is a collection of symptoms (including raised blood glucose levels, blood fats, blood pressure and carrying weight around the middle) which occur together and can increase the risk of type 2 diabetes, heart disease and stroke.

The researchers found that first-degree male relatives of women with PCOS do indeed have a higher risk of the metabolic syndrome. In fact 42% of fathers and 22% of brothers of women with PCOS had the metabolic syndrome, compared to 32% and 9% of the general population, respectively. Although not the case in women with PCOS and their female relatives, this study found that body mass index (BMI) accounted for the higher risk in male relatives – once they controlled for BMI, the rates were similar to the general population.

The authors conclude, however, that screening for metabolic syndrome should be considered in male first-degree relatives of women with PCOS.

Coviello et al. High prevalence of metabolic syndrome in first-degree male relatives of women with polycystic ovary syndrome is related to high rates of obesity. J Clin Endocrinol Metab 2009;94:4361-4366.

November 2009: Combined diet and exercise the key to improving insulin resistance

Combining diet and exercise, rather than diet or exercise alone, leads to significantly greater improvements in body fat distribution and insulin resistance, according to the findings of a new study. Insulin resistance is the underlying problem in type 2 diabetes and PCOS.

Researchers from the University of Arkansas for Medical Sciences studied 34 obese older men and women who were randomised to one of four groups: the first two groups aimed to lose weight, one through diet (reducing their energy intake) and the second through exercise plus diet. A third group underwent exercise training without weight loss (they ate more to prevent weight loss due to their increased activity) and a fourth group acted as controls. The study was designed so that the two weight loss groups lost a similar amount of weight.

The researchers found that while weight loss was similar in the diet and exercise + diet groups, the latter group lost significantly more visceral fat (also known as abdominal fat, or fat stored around the middle) compared to those who dieted only or the exercise only group. Improvements in insulin resistance were also significantly greater in the exercise + diet group compared to the diet or exercise only groups.

The researchers conclude that a combination of diet and exercise is the optimal intervention for improving body fat distribution and insulin resistance.

Coker et al. The Impact of Exercise Training Compared to Caloric Restriction on Hepatic and Peripheral Insulin Resistance in Obesity. The Journal of Clinical Endocrinology & Metabolism Vol. 94, No. 11 4258-4266

November 2009: Exercise, not genes, predicts body fat levels

We can’t always blame our genes for being overweight according to Finnish researchers – it’s the amount of exercise we get that influences how much fat we carry.

While exercise is thought to reduce body fat levels most studies have only been short-term and many are limited by genetic selection. So these researchers studied 16 middle-aged same-sex twin pairs (both identical and non-identical) who had different physical activity levels (ie one twin was significantly more active than the other) over a 32 year follow-up period. They found that compared to their active siblings, the physically inactive twins had:

· 50% more visceral fat (also know as abdominal fat or fat stored around the middle)

· 170% more liver fat

· 54% more intramuscular fat (fat located throughout muscle)

All three types of fat are considered ‘high risk’, contributing to diabetes and heart disease risk.

The researchers also found that fitness level (measured by peak oxygen uptake) was inversely associated with intramuscular and visceral fat, suggesting that the twins who were fitter were less likely to be carrying excess body fat.

The researchers conclude that regular physical activity appears to be an important factor in preventing the accumulation of high-risk fat over time, even after controlling for genetics and childhood environment. They recommend that the role of regular leisure-time physical activity should be emphasized in the prevention and treatment of obesity.

Leskinen et al. Leisure-time physical activity and high-risk fat: a longitudinal population-based twin study. International Journal of Obesity 2009; 33: 1211–1218

April 2009: Exercise reduces loss of lean muscle during weight loss

Exercising at a moderate or vigorous level during weight loss can reduce the loss of lean muscle tissue associated with dieting but doesn’t affect abdominal fat loss, according to the findings of a new study.

Researchers from the Wake Forest University Schoolof Medicine in the US studied 112 overweight and obese postmenopausal women who were assigned to one of three 20 week interventions:

- Calorie restriction (dieting) only

- Calorie restriction plus moderate-intensity aerobic exercise

- Calorie restriction plus vigorous-intensity aerobic exercise

The exercise involved walking on a treadmill at an intensity of 45-50% (moderate intensity) or 70-75% (vigorous intensity) of heart rate reserve. The study was designed so that the energy deficit (the difference between what they ate and how much energy they used up with exercise) was the same for each group.

Ninety-five women completed the study and lost, on average, 12.1kg over the 20 week study. The researchers found that all groups achieved a similar reduction in abdominal visceral fat – around 25%. However those in the vigorous-intensity group increased their fitness levels (measured by VO₂max) to a greater extent and increased fitness levels were related to loss of abdominal fat. They also found that diet only group lost more lean body mass than either exercise group. Loss of lean muscle reduces metabolic rate and can make continued weight loss and maintenance more difficult.

Previous studies have shown similar findings. For example a similar study (comparing diet only versus diet plus exercise over 20 weeks) was recently published involving 94 overweight and obese women with polycystic ovary syndrome (PCOS). Like the study above, both the diet only and exercising groups lost similar amounts of weight (in this study it was 8.7-10.6%) but the researchers found that almost 50% of the weight loss in the diet only group (3.8kg) was due to a reduction in fat free mass. The exercising groups (either aerobic or combined aerobic-resistance training) lost approximately 45% more fat mass and 60% less fat free mass than the diet only group.

Nicklas et al. Effect of exercise intensity on abdominal fat loss during calorie restriction in overweight and obese postmenopausal women: a randomized, controlled trial. Am J Clin Nutr 89: 1043-1052, 2009.

Thomson et al. The effect of a hypocaloric diet with and without exercise training on body composition, cardiometabolic risk profile, and reproductive function in overweight and obese women with polycystic ovary syndrome. J Clin Endocrinol Metab 2008.

June 2010: Heart disease risk high in women with PCOS and diabetes

Women with PCOS who are obese, who smoke, who have abnormal blood fats or blood pressure or who have impaired glucose tolerance (pre-diabetes) are at risk of cardiovascular disease
Women with PCOS who have themetabolic syndrome and/or type 2 diabetes mellitus are at highrisk for cardiovascular disease
All women with PCOS should have measurements of their body mass index (based on weight and height), waist circumference, blood fats, blood glucose levels and blood pressure
Women with PCOS who are obese, older or who have a history of gestational diabetesor family history of type 2 diabetes should have an oral glucose tolerance test to check for diabetes
All women with PCOS should be assessed for mood disorders including depression.
Lifestyle managementis recommended for women with PCOS to reduce the risk of cardiovascular disease and should aim to improve blood fats – this should include an initial aim of 5-10% weight loss, with a longer-term goal of 10-20% weight loss and maintenance. If risk factors persist after lifestyle changes, insulin-sensitising medications (such as the diabetes medication metformin) and blood pressure and cholesterol-lowering medications should be added.