Waist-to-Hip Ratio Is a Better Cardiac Predictor Than BMI

Body-mass index (BMI) has been studied widely as a measure of obesity and a cardiovascular risk factor, but some findings have suggested that waist-to-hip ratio (WHR) might predict cardiovascular morbidity more accurately. To test this hypothesis, investigators calculated BMI and WHR in more than 12,000 patients with first myocardial infarctions and more than 14,000 age- and sex-matched controls from 52 countries.

Subjects in the highest BMI quintile had significantly greater risk for MI than those in the lowest quintile (odds ratio, 1.44), but the association declined after adjustment for WHR (OR, 1.12) and became insignificant after further adjustment for other risk factors. In contrast, when the highest and lowest quintiles of WHR were compared, high WHR conferred a significantly increased MI risk after multivariate adjustment (OR, 1.75). In most subgroups studied, risk associated with a 1-SD (standard deviation) increase was greater for WHR than for waist or hip circumference and was weakest for BMI. Worldwide, more MIs could be attributed to obesity when measured by WHR than by BMI, suggesting that the cardiovascular burden of obesity has been underestimated by studies based on BMI.

References:

1. Yusuf S et al. Obesity and the risk of myocardial infarction in 27 000 participants from 52 countries: A case-control study. Lancet 2005 Nov 5; 366:1640-9.