Objective: Asian Indians have a high risk of developing glucose intolerance with small increments in their BMI. They generally have high upper-body adiposity, despite having a lean BMI. Therefore, this analysis was performed to find out the normal cutoff values for BMI and upper-body adiposity (waist circumference [WC] or waist-to-hip ratio [WHR]) by computing their risk associations with diabetes.
Research design and methods: The risk of diabetes with stratified BMI, WC, or WHR was computed in 10,025 adults aged > or =20 years without a history of diabetes, and they were tested by oral glucose tolerance tests, using World Health Organization criteria. The calculations were performed separately in men and women using diabetes as the dependent variable versus normoglycemia (normal glucose tolerance) in multiple logistic regression analyses. Age-adjusted and stratified BMI, WC, or WHR were used as the independent variables, using the first stratum as the reference category. The upper limit of the stratum above which the risk association became statistically significant (P < 0.05) was considered to be the cutoff for normal values.
Results: Normal cutoff values for BMI was 23 kg/m(2) for both sexes. Cutoff values for WC were 85 and 80 cm for men and women, respectively; the corresponding WHRs were 0.88 and 0.81, respectively. Optimum sensitivity and specificity obtained from the receiver operator characteristic curve corresponded to these cutoff values.
Conclusions: The cutoff value for normal BMI for men and women was 23 kg/m(2). The cutoff values for WC and WHR were lower in women than in men. The values were significantly lower compared with the corresponding values in white populations.