Waist Size, Regardless Of BMI, Linked To Diabetes Risk

Waist circumference is strongly and independently linked to diabetes type two risk, even after accounting for body mass index (BMI), and should be measured more widely for estimating risk, researchers from the Medical Research Council (MRC) Epidemiology Unit, UK, reported in PLoS Medicine. The authors explained that overweight people with a large waist, over 102cm (40.2 inches) for men and over 88cm (34.6 inches) for women, have approximately the same or higher risk of eventually developing diabetes type 2 as obese individuals.
Dr Claudia Langenberg and team gathered data on over 340,000 individuals from eight European countries to determine what their future risk of developing diabetes type 2 might be.
Dr Claudia Langenberg, said:

"Type 2 diabetes is a serious and increasingly common disease. More than a third of the UK adult population is overweight and at increased risk of diabetes, but they are not systematically monitored for this risk. Our findings suggest that if their waist circumference is large, they are just as likely to develop the condition as if they were obese.
We do not suggest replacing BMI as a core health indicator, but our results show that measuring waist size in overweight patients allows doctors to 'zoom in' on this large population group and identify those at highest risk of diabetes. These people can then be offered lifestyle advice, which can reduce their risk of developing the disease."

Diabetes type 2 is a long-term condition that occurs when the person's body cannot produce enough insulin, or when the cells in the body do not react properly to insulin. The exact causes of type 2 diabetes are not precisely understood, but experts say that being obese or overweight are the main modifiable risk factors.
Langenberg and team set out to determine what the link between BMI, waist size and the likelihood of developing diabetes type 2 might be - they also aimed to find out what the risks were separately for men and women. They gathered data from the European Union funded InterAct Study, consisting of 12,403 individuals with diabetes type 2 who had developed the disease during a 15-year follow up.
They found that:

Overweight people with large waists have the same or higher risks of eventually developing type 2 diabetes as obese individuals

• 7% of males with a large waist who were overweight eventually developed diabetes type 2 within ten years
• 4% of females with a large waist who were overweight eventually developed diabetes type 2 within ten years
• Large-waisted overweight men and women were found to have either the same or higher risk of eventually developing diabetes type 2, compared to obese individuals
• Normal weight men with a small waist had only a 1.6% chance of developing the disease
• Normal weight women with a small waist had a 0.6% risk of developing the disease
• Pear-shaped people - those who were overweight but had a small waist - were found to have a relatively low risk of developing diabetes type 2
• Women with a BMI greater than 35 (obese women) with a large waist were nearly 32-times more likely to eventually develop diabetes type 2 compared to thin women with a small waist
• Obese men with a large waists were 22-times more likely to develop the disease compare to their lean and small-waisted counterparts

Principal Investigator of the InterAct Study, Professor Nick Wareham, said:

"This is one of the most comprehensive studies of lifestyle and diabetes risk to date, not just in scale, but in the powerful prospective design which allows us to follow a population over a long period of time to see how and why disease develops. The results of this important research will help inform new strategies for the prevention of this devastating condition that affects almost three million people in the UK."