A new study has indicated that a higher rate of diabetes seen among adult Americans when compared to peers in England is explained primarily by a larger waist size rather than conventional risk factors such as obesity.
Researchers from the RAND Corporation, University College London and the Institute for Fiscal Studies in London say the findings offer more evidence that accumulating fat around the mid-section poses a health risk and suggests that studies of diabetes risk should emphasize waist size along with traditional risk factors.
"Americans carry more fat around their middle sections than the English, and that was the single factor that explained most of the higher rate of diabetes seen in the United States, especially among American women," said James P. Smith, one of the study's author and corporate chair of economics at RAND, a nonprofit research organization.
"Waist size is the missing new risk factor we should be studying."
About 16 percent of American men report having diabetes as compared to 11 percent of English men. About 14 percent of American women have diabetes, compared to 7 percent among English women.
American men had waists that averaged 3 centimeters larger than their English peers and the waists of American women were 5 centimeters bigger than English women. American women were significantly more likely to face higher risk because of their waist size when compared to English women (69 percent to 56 percent), while American men had only a slightly higher waist risk than their English peers.
The higher waist size of Americans posed more risk compared to their English peers across most body mass index categories. For example, among women with normal weight, 41 percent of American women were categorized as having high waist risk compared to 9 percent of English women.
The study concludes that waist circumference explains a substantial proportion of the higher diabetes rate in America for men and virtually all the higher rate seen among women.
Researchers say there may be many reasons why Americans have larger waists than their English peers. It may be caused by different rates of physical activities through exercise or daily activities, diet differences or perhaps other social and environmental factors such as stress that occur in the United States.
The Journal of Epidemiology and Community Health have published the findings online.