Metabolic risk factors in the normolipidemic male patients with angiographically defined coronary artery disease

The relationship of plasma lipid and apolipoprotein (apo) concentrations and plasma insulin response to oral glucose load to angiographically determined coronary artery disease (CAD) was investigated in 65 normolipidemic (plasma cholesterol less than 230 mg/dl and plasma triglyceride less than 150 mg/dl) males. According to the results of coronary angiography, the patients were divided into 2 groups: patients with normal coronary artery, NCA group (n = 21); and patients with coronary artery disease, CAD group (n = 44). No significant differences in concentrations of plasma cholesterol and triglyceride were observed between the CAD and NCA groups. In the CAD group cumulative lifetime tobacco consumption was higher and high density lipoprotein (HDL) cholesterol concentration was lower than those in the NCA group. The variables that correlated with the severity of CAD, defined by the number of lesions and percent stenosis, were levels of plasma apo A-I and apo B. Prevalence of subjects with reduced oral glucose tolerance did not differ between 2 groups. However, hyperinsulinemic response to oral glucose load was present in the CAD group. HDL-cholesterol concentration, the sum of plasma insulin levels and the magnitude of the early insulin response during oral glucose challenge were accurate predictors of the presence of but not the severity of CAD. Multivariate analysis of the data confirmed the independent effect of plasma levels of apo A-I and apo B on the severity of CAD. The present data indicated that plasma levels of apo A-I and apo B were powerful discriminators in the normolipidemic CAD patients and that a high insulin response might be an indicator of enhanced susceptibility to the distinct coronary atherosclerosis.