Warning over waistline link to type 2 diabetes

“Belly fat clearest sign of type 2 diabetes risk,” The Guardian reports. This comes as Public Health England publishes a report highlighting the links between bulging waistlines, obesity and type 2 diabetes risk.

According to a new report, men whose waist size is over 102cm (40.2 inches) are five times more likely to develop diabetes than those with a smaller waist size. Women with a waist over 88cm (34.7 inches) are three times more likely to develop the condition.

The report says that being overweight or obese is the main avoidable risk factor for type 2 diabetes.

The condition is now a major public health issue, with all types of diabetes projected to rise to 4.6 million – nearly 10% of the adult population – by 2030.

Some people may have the misconception that type 2 diabetes is an inconvenience, like back pain or arthritis, but not especially serious. This is not the case.

Type 2 diabetes can lead to blindness (diabetic retinopathy), heart problems and even reduce blood supply to the limbs, which can lead to the affected limb being amputated. People with type 2 diabetes are 15 times more likely to require an amputation than the population at large.

If you are concerned about your weight, it is recommended that you measure you waist size and ask your GP for advice. If necessary, they can arrange testing for the condition. The sooner type 2 diabetes is treated, the less likely it is to cause complications.

The key to reducing the risk of diabetes is losing weight, which can be achieved through a healthy diet and being more active.

The NHS Weight Loss plan can help you achieve both these goals.

Who produced the report?

The report was produced by Public Health England (PHE), a government body set up to protect and improve people’s health, and reduce health inequalities. PHE is part of the Department of Health and came into being in April 2013.

What is the aim of the report?

The report draws together a multitude of facts and figures to describe the relationship between obesity and type 2 diabetes. Its aim is to support decisions by public health policymakers and practitioners. It points out that, currently, 90% of adults with type 2 diabetes are overweight or obese, and that both conditions are on the increase in the UK.

Diabetes

The report explains that diabetes is a condition in which the body does not produce sufficient insulin to regulate blood glucose levels, or where the insulin produced is unable to work effectively. There are two main types of diabetes: 1 and 2.

The report focusses on type 2 diabetes, which accounts for at least 90% of all cases and is easily preventable by making lifestyle changes. It points out that obesity is only associated with type 2 diabetes.

Type 1 diabetes is an autoimmune condition that has no association with obesity or other lifestyle factors, and is not preventable; people are born with the condition (though symptoms do not usually develop until around puberty).

Link between obesity and diabetes

The report says that being overweight or obese, with a body mass index (BMI) of 25 or above, is the main modifiable risk factor for type 2 diabetes. In England, obese adults are five times more likely to be diagnosed with the condition than adults of a healthy weight, with a greater risk among people who have been obese for longer.

In addition, a recent study found that severely obese people (with a BMI of 40 or above) are at even greater risk compared to obese people with a lower BMI (30.0-39.9).

This, it claims, may have significant implications for the NHS, given the increasing trend of severe obesity in adults.

In particular, a large waist circumference is associated with increased risk of diabetes. Men with a raised waist circumference (greater than 102cm) are five times as likely to have doctor-diagnosed diabetes, compared to those without a raised waist circumference.

Women with a raised waist circumference (greater than 88cm) are more than three times as likely to get the condition.

The precise mechanism for this association remains unclear, says PHE. Some hypotheses include:

Abdominal obesity may cause fat cells to release inflammatory chemicals that disrupt the body’s response to insulin.
Obesity may trigger changes to the body's metabolism that cause adipose (fat) tissue to release substances involved in the development of insulin resistance.

It is also uncertain why not all people who are obese develop type 2 diabetes, and why not all people with type 2 diabetes are obese.

Prevalence of obesity and diabetes

The report states that in 2012:

an estimated 62% of adults (aged 16 years and over) were overweight or obese in England (with a BMI of 25 or above)
24.7% were obese (with a BMI of 30 or above)
2.4% were severely obese (with a BMI of 40 or above)

The prevalence of obesity has increased sharply since the 1990s, and some forecasts predict that by 2050, obesity will affect 60% of adult men and 50% of adult women.

The rise in obesity has led, and will continue to lead, to a parallel rise in diabetes.

In 2013, 2.7 million – equivalent to 6% of the adult population – had diagnosed diabetes in England, representing an increase of 137,000 people since 2012.

However, when undiagnosed cases are taken into account, it has been estimated that the true prevalence in England is around 3.2 million, or 7.4% of the adult population.

This figure is projected to rise to 4.6 million, or 9.5% of the adult population, by 2030.

Approximately a third of this increase is attributable to obesity, while the rest is due to ageing and the changing ethnic structure of the population.

Other risk factors

Although obesity and being overweight are the major risk factors for type 2 diabetes, other risk factors include:

Increasing age. The National Institute for Health and Care Excellence (NICE) states that being older than 40, or older than 25 for some black and minority ethnic groups, is an important risk factor for developing type 2 diabetes.
Lifestyle factors. Both obesity and type 2 diabetes are strongly associated with unhealthy diet and physical inactivity.
Ethnicity. All minority ethnic groups (with the exception of Irish) have a higher risk of diagnosed diabetes than the general population. For example, women of Pakistani ethnic origin are five times more likely, and those of Bangladeshi or Caribbean origin three times more likely, to be diagnosed with diabetes compared to women in the general population. Type 2 diabetes also affects people of South Asian, African-Caribbean, Chinese or black African descent up to a decade or more earlier than white Europeans.
Deprivation. In England, type 2 diabetes is 40% more common among people in the most deprived quintile (where a sample of the population is divided into fifths), compared with those in the least deprived quintile. People in social class V (unskilled manual) are three-and-a-half times more likely to be ill as a result of diabetic complications than those in social class I (professional), while the short-term mortality risk from type 2 diabetes is higher among those living in more deprived areas in England.

Health implications

People with diabetes are at risk of a range of health complications. Uncontrolled diabetes is associated with cardiovascular disease (CVD), blindness, amputation, kidney disease and depression.

It can also result in lower life expectancy.

Life-long diabetes can also have a profound impact on lifestyle, relationships, work, income, and health and wellbeing.

The report points out that diabetic eye disease is the leading cause of preventable sight loss in people of working age, while up to 100 people a week have a limb amputated in the UK as a result of diabetes.

In England, diabetes is a major cause of mortality, with over 23,000 additional deaths in 2010-11.

Cost

In the UK, it is estimated that overweight, obesity and related illnesses cost the NHS £4.2 billion in 2007, and these costs are predicted to reach £9.7 billion by 2050.

Wider total costs to society (such as loss of productivity) of overweight and obesity are estimated to reach £49.9 billion by 2050. To put that figure in context, that would be enough to pay the annual wages of just under three-and-a-half million newly qualified nurses.

A recent economic study estimated that in 2010-11 the cost of treating type 2 diabetes and its associated complications in the UK was £8.8 billion. The indirect costs (such as loss of productivity due to increased death and illness and the need for informal care) were £13 billion.

What is to be done?

The report itself makes no recommendations for the public, nor does it encourage people to whip out the tape measure, as some newspaper reports have implied.

However, according to a BBC report, PHE’s chief nutritional adviser, Dr Alison Tedstone, urged people to "keep an eye on your waist measurement" as losing weight is "the biggest thing you can do" to combat the disease.

"People get it wrong, particularly men,” she is reported as saying.

"They measure their waist under their bellies, saying they haven't got fatter because their trouser size is the same, forgetting they're wearing their trousers lower and lower.

"So the tip is to measure across the belly button."