Apolipoprotein B as the best predictor of coronary artery disease in Iranian normolipidemic patients

Objectives: A relatively high proportion of Iranian patients with coronary artery disease (CAD) have normal levels of traditional lipid risk Factors and show early onset of CAD. In this study we examined the roles of apolipoprotein S (apoB), apolipoprotein AI (apoAI) and lipoprotein (a) [LP(a)] in predicting coronary heart disease in normolipidemic patients and those with premature CAD (age less than or equal to 50). Design and methods: Serum levels of apoB, apoAI, and LP(a) were determined in a total of 567 Iranian patients who were candidates for coronary angiography. A subgroup of 142 patients (93 males, 49 females) with normal levels of classical lipid risk factors, and a subgroup of patients (130 males, 71 females) with age below 50 years were separately assessed for coronary risk factors. Results: ApoB concentrations were significantly higher in patients with CAD (CAD+) relative to patients without CAD (CAD-) in the two subgroups. Multiple logistic regression after controlling for age and others risk factors showed apoB as the best determinant of CAD in the normolipidemic subgroup (OR, 4.3, p < 0.001) and in the men aged less than or equal to 50 (OR, 5.7, p < 0.001). ApoB was the best predictor of CAD in a subgroup of very young patients (age less than or equal to 40, n = 77, OR, 8.6, p < 0.009). There was a significant correlation between severity of atherosclerosis and serum apoB concentration in the normolipidemic subgroup (r = 0.72, p < 0.008). Conclusions: Our data indicate that serum concentration of apoB is the best discriminating factor to predict the presence or absence of atherosclerosis in Iranian normolipidemic individuals and young patients undergoing coronary angiography. (C) 2001 The Canadian Society of Clinical Chemists. All rights reserved.