Central obesity and multivariable cardiovascular risk as assessed by the Framingham prediction scores

Abstract

To evaluate the role of measurements of central obesity in the multivariable prediction of cardiovascular risk using the Framingham risk scores, we studied 4,175 representative men from Australian cities, free of heart disease, stroke, and diabetes in 1989, and followed the cohort for mortality to 2004. Baseline lipids, blood pressure, and current cigarette smoking were recorded. Obesity was assessed by body mass index, waist circumference (WC), and waist-to-hip ratio (WHR) by strictly standardized methods. The Framingham equations were strong predictors of coronary heart disease (CHD) and cardiovascular disease (CVD) deaths. Of the obesity measurements, WHR and WC predicted deaths using Cox proportional hazards regression but body mass index did not. In the multivariable analyses, WHR was an independent predictor of CHD deaths, and WHR and WC were independent predictors of CVD deaths. There was little or no attenuation of hazard ratios for WHR and WC after correction for the Framingham scores. The 2 measurements of central obesity were more strongly predictive of CHD and CVD deaths in subjects at the lower levels of Framingham risk. In contrast, cigarette smoking risk appeared to contribute more in the higher Framingham risk categories. In conclusion, central obesity significantly and independently contributes to cardiovascular outcomes and to residual risk after accounting for the Framingham equations.