Central obesity and cigarette smoking are key determinants of cardiovascular disease deaths in Australia: A public health perspective

Abstract

Background Our objective is to develop a parsimonious model to predict coronary heart disease (CHD) and cardiovascular disease (CVD) deaths using individual components of the Framingham risk score plus measures of central obesity. Methods 15 year mortality follow-up of 8662 representative Australian adults in the National Heart Foundation Risk Factor Prevalence Survey of 1989, excluding those with a baseline history of heart disease, stroke or diabetes. Measures included blood pressure, fasting lipids, smoking history, body mass index (BMI), waist circumference (WC) and waist to hip ratio (WHR). Multivariable logistic regression was used to assess the effects of the Framingham risk variables and central obesity variables on cardiovascular disease mortality. Results Smoking status, high density lipoprotein cholesterol (HDL-C) and the total cholesterol (TC) to HDL-C ratio were significant univariate predictors of CHD deaths. These together with systolic blood pressure were significant predictors of CVD deaths. The obesity measures of WC and WHR were significant univariate predictors but BMI was not. In multivariable analyses, only smoking status and waist to hip ratio were identified as key independent risk factors for CHD and CVD deaths, although TC to HDL-C ratio contributed minimally to CHD deaths. Receiver operator characteristic (ROC) curves for the Framingham risk score in comparison to the WHR plus smoking model were virtually identical, with no added effect of the lipid ratio. Conclusion The preferred model for predicting CHD and CVD deaths uses central obesity plus smoking with no added influence of measured lipids or blood pressure. A public health focus on identifying and modifying central obesity is at least as important as the measurement and treatment of lipids and hypertension.