Background: Among patients with coronary artery disease (CAD), high-density lipoprotein cholesterol (HDL-C) is a cardiac protective factor. In contrast, body mass index (BMI) is inversely related to mortality, and this is known as the obesity-mortality paradox. The relationship of HDL-C and BMI to mortality, however, has not been clarified well. The aim of this study was to evaluate the impact of HDL-C and BMI on mortality among CAD patients.
Methods and results: A cohort of 1,114 angiographic CAD patients from the ET-CHD registry during 1997-2003 in Taiwan was studied. The subjects were categorized into 4 groups according to BMI ≥ 25 kg/m(2) (overweight/obese) or BMI <25 kg/m(2) (normal/underweight), and HDL-C higher or lower than the median of 40 mg/dl in men and 45 mg/dl in women. At a mean follow-up of 5.3 years, cardiac and all-cause death were the primary endpoints. On multivariate analysis, low HDL-C predicted higher cardiac and all-cause mortality in normal/underweight patients (hazard ratio [HR], 1.59; 95% confidence interval [CI]: 1.08-2.33; and 1.65, 95% CI: 1.25-2.19, respectively). In contrast, high BMI predicted lower cardiac and all-cause mortality in patients with low HDL-C (HR, 0.78; 95% CI: 0.54-1.14; and 0.66, 95% CI: 0.49-0.88, respectively).
Conclusions: Among CAD patients in Taiwan, those with low HDL-C and normal/underweight had higher risk of mortality.