Racial and Ethnic Differences in Anthropometric Measures as Risk Factors for Diabetes

OBJECTIVE The study objective was to examine the impact of race/ethnicity on associations between anthropometric measures and diabetes risk. RESEARCH DESIGN AND METHODS A total of 136,112 postmenopausal women aged 50–79 years participating in the Women’s Health Initiative without baseline cancer or diabetes were followed for 14.6 years. BMI, waist circumference (WC), and waist-to-hip ratio (WHR) were measured in all participants, and a subset of 9,695 had assessment of whole-body fat mass, whole-body percent fat, trunk fat mass, and leg fat mass by DXA. Incident diabetes was assessed via self-report. Multivariate Cox proportional hazards regression models were used to assess associations between anthropometrics and diabetes incidence. RESULTS During follow-up, 18,706 cases of incident diabetes were identified. BMI, WC, and WHR were all positively associated with diabetes risk in each racial and ethnic group. WC had the strongest association with risk of diabetes across all racial and ethnic groups. Compared with non-Hispanic whites, associations with WC were weaker in black women (P < 0.0001) and stronger in Asian women (P < 0.0001). Among women with DXA determinations, black women had a weaker association with whole-body fat (P = 0.02) but a stronger association with trunk-to-leg fat ratio (P = 0.03) compared with white women. CONCLUSIONS In postmenopausal women across all racial/ethnic groups, WC was a better predictor of diabetes risk, especially for Asian women. Better anthropometric measures that reflect trunk-to-leg fat ratio may improve diabetes risk assessment for black women.