Body Mass Index and Body Girths as Predictors of Mortality in Black and White Women

BACKGROUND: The high prevalence of obesity in black women has been hypothesized to contribute to higher rates of coronary heart disease and total mortality. Investigators have recently refined the study of obesity by differentiating anatomic patterns of the physical location of adipose tissue on the body. We examined fat patterning as a predictor of mortality in black women. METHODS: Body mass index (BMI) and body girths were examined as predictors of all-cause and coronary heart disease mortality during 25 to 28 years of follow-up in black and white women in the Charleston Heart Study. RESULTS: The BMI was associated with all-cause and coronary heart disease mortality in white, but not black, women. After controlling for differences in BMI, the risk of all-cause mortality was greater in white women with larger chest and abdominal girths, while midarm girths were inversely associated with mortality. The hazard at the 85th percentile relative to the 15th percentile of abdomen/midarm ratio was 1.44 in models that included BMI, education, and smoking as covariates. In black women, the girths were not predictive of either all-cause or coronary heart disease mortality. CONCLUSIONS: The failure of BMI and fat patterning to predict mortality in black women challenges previously held assumptions regarding the role of overweight in the higher mortality experienced by black women.