Measures of Obesity and Cardiovascular Risk Among Men and Women

Objectives We examined associations between anthropometric measures (body mass index BMI, waist circumference WC, waist-to-hip ratio WHR, waist-to-height ratio WHtR) and risk of incident cardiovascular disease (CVD, including nonfatal myocardial infarction, nonfatal ischemic stroke, cardiovascular death). Background Controversy exists regarding the optimal approach to measure adiposity, and the utility of BMI has been questioned. Methods Participants included 16,332 men in the Physicians’ Health Study (mean age 61, 1991) and 32,700 women in the Women’s Health Study (mean age 61, 1999). We used Cox proportional hazards models to determine relative risks (RR) and 95% confidence intervals (CI) for developing CVD according to self-reported anthropometric indices. Results A total of 1505 CVD cases occurred in men, and 414 occurred in women (median follow-up, 14.2 and 5.5 years, respectively). While WHtR demonstrated statistically the strongest associations with CVD and best model fit, CVD risk increased linearly and significantly with higher levels of all indices. Adjusting for confounders, the RR (CI) for CVD was 0.58 (0.32–1.05) for men with the lowest WHtR (<0.45) and 2.36 (1.61–3.47) for the highest WHtR (≥0.69; versus WHtR 0.49-<0.53). Among women, the RR (95% CI) was 0.65 (0.33– 1.31) for those with the lowest WHtR (<0.42) and 2.33 (1.66–3.28) for the highest WHtR (≥0.68; versus WHtR 0.47- <0.52). Conclusions WHtR demonstrated statistically the best model fit and strongest associations with CVD. However, as compared to BMI, differences in cardiovascular risk assessment using other indices were small and likely not clinically consequential. Our findings emphasize that higher levels of adiposity, however measured, confer increased risk of CVD.