Plasma apolipoprotein B and VLDL-, LDL-, and HDL- cholesterol as risk factors in the development of coronary artery disease in male patients examined by angiography

To assess the potential use of plasma apolipoprotein B (ApoB) as a risk factor for coronary artery disease, this apolipoprotein was quantified by electro-immunoassay in 161 male patients with angiographically documented coronary atherosclerosis and 72 male patients with normal coronary arteries. In addition to ApoB, the analyzed lipoprotein profile included plasma total cholesterol, plasma triglyceride and VLDL-, LDL- and HDL-cholesterol levels. Age, plasma cholesterol, triglyceride, and VLDL- and LDL-cholesterol were significantly greater ( P < 0.05) for patients with coronary artery disease than for patients with normal arteries. In contrast, there was no difference in the mean levels of HDL-cholesterol between these 2 groups of patients. However, patients with HDL-cholesterol less than 40 mg/dl had a higher rate of coronary artery disease than those with HDL-cholesterol greater than 40 mg/dl ( P < 0.05). The results of multivariate analysis showed that age and plasma cholesterol were the 2 variables most significantly ( P < 0.01) related to the presence of coronary artery disease. However, in a subgroup of patients with plasma cholesterol less than 265 mg/dl, the most reliable variable was ApoB ( P < 0.01). For patients under 50 years of age ApoB and LDL-cholesterol were the most significant variables ( P < 0.05), whereas for patients at 50 years of age or older VLDL-cholesterol was the most significant variable ( P < 0.01). Results of this study indicate that measurement of ApoB may offer important predictive value for coronary artery disease, expecially at lower levels of plasma cholesterol. Whether this and other conclusions also apply to general population, remains to be established in future studies.