Waist circumference compared with other obesity parameters as determinants of coronary artery disease in essential hypertension: a 6-year follow-up study

This study aimed to assess the predictive role of body mass index (BMI), waist circumference (WC) and the waist-to-hip ratio (WHR) for the incidence of coronary artery disease (CAD) in a cohort of essential hypertensive patients. We followed up 2266 essential hypertensive individuals (mean age, 57.8 years; males, 1083; office blood pressure (BP), 143/89 mm Hg) who were free of cardiovascular disease for a mean period of 6 years. All subjects had at least one annual visit and, at baseline, underwent blood sampling and a complete echocardiographic study to determine the left ventricular (LV) mass index. CAD was defined as a history of myocardial infarction or significant coronary artery stenosis that was revealed by angiography or a coronary revascularization procedure. The incidence of CAD throughout the follow-up period was 2.33%. Hypertensive individuals who developed CAD (n=53) had a greater baseline WC (101.1 +/- 11.7 vs. 96.4 +/- 12 cm, P=0.005), WHR (0.94 +/- 0.07 vs. 0.89 +/- 0.08 cm, P<0.0001) and LV mass index (117 +/- 26.8 vs. 103.3 +/- 27 g m(-2), P<0.0001) compared with those without CAD at follow-up (n=2213), whereas no difference was observed compared with the baseline office BP and BMI values (P=NS for all). Using a multivariate Cox regression model, WC (hazard ratio (HR) 1.037, P=0.002) and LV mass index (HR 1.010, P=0.044) were found to be independent predictors of CAD. In essential hypertensive patients, WC could predict the future development of CAD, whereas BMI and WHR showed no independent prognostic value. These findings suggest that WC constitutes an easy clinical tool to assess risk in hypertension among individuals with obesity.