Men who had larger waists (assessed using waist circumference and waist-hip ratio) or higher overall body fat (indicated by BMI) had a greater risk of developing type 2 diabetes. The researchers grouped the study participants into five groups according to their waist size. Compared to those in the group with the smallest waists (29-34 inches), the other groups (34.3-35.9 inches, 36-37.8 inches, 37.9-39.8 inches, 40-62 inches) were 2, 3, 5 and 12 times more likely to develop diabetes, respectively. Similarly, risk was 2, 3, 4 and 7 times greater when waist-hip ratio was measured in men; and 1, 2, 3 and 8 times greater when BMI was measured.
"Both BMI and waist circumference are useful tools to assess health risk," said the study's lead author, Youfa Wang, PhD, MD, assistant professor with the Center for Human Nutrition at the Johns Hopkins Bloomberg School of Public Health. "But abdominal fat measured by waist circumference can indicate a strong risk for diabetes whether or not a man is considered overweight or obese according to his BMI."
The authors suggest that the currently recommended waist circumference cutoff of 40 inches for men may need to be lowered. "Many of the men who developed type 2 diabetes had measurements lower than the cutoff," explains Wang, "and the risk associated with waist circumference increased at a much lower level."
While nearly 80 percent of the men in this cohort who developed type 2 diabetes could be identified using a BMI of 25--the cutoff for overweight--only half (50.5 percent) had a
Contact: Tim Parsons
Johns Hopkins University Bloomberg School of Public Health