Relationship of blood cholesterol and apoprotein B levels to angiographically defined coronary artery disease in young males.

Abstract

Coronary heart disease is mainly caused by the effects of obstruction to blood flow in the coronary arteries from discrete mural lesions that encroach into the lumen and usually occur in arteries that are involved by atherosclerosis. Even though the level of certain lipoproteins is indisputably related to the degree of this atherosclerotic involvement of the coronary arteries, the question of whether lipoproteins are also associated with the obstructive lesions remains uncertain. This study addressed the question in 53 males (age, 44.6 +/- 4.9 y) with premature coronary heart disease and angiographically proven coronary artery disease. The cholesterol, triglyceride, high-density lipoprotein, apoprotein B, and apoprotein A-I levels were compared by linear correlation to semiquantitative angiographic measures of coronary artery disease severity (coronary stenosis score and mean coronary stenosis score), the extent of mural involvement (coronary atheromatous score and mean coronary atheromatous score), and also the number of normal coronary artery segments, an alternative severity score (Jenkins), and left ventricular function score. Age, past and present cholesterol, low-density lipoprotein cholesterol, and apoprotein B levels correlated directly with the extent of disease (r = 0.27, 0.46, 0.29, 0.26, 0.35, respectively, P < 0.05 with coronary atheromatous score; r = 0.29, 0.44, 0.33, 0.30, 0.35, respectively, P < 0.05 with mean coronary atheromatous score). Age and New York Heart Association angina functional class correlated directly with disease severity (r = 0.25, 0.31, respectively, P < 0.05 with coronary stenosis score; r = 0.25, 0.34, respectively, P < 0.05 with mean coronary stenosis score). There was an inverse association between age, past and present cholesterol, low-density lipoprotein cholesterol, and apoprotein B levels with the number of normal segments (r = -0.23, -0.46, -0.38, -0.35, -0.39, respectively, P < 0.05). Multiple regression analysis was undertaken with lipoproteins and age as independent variables and angiographic scores as dependent variables; the apoprotein B level was the most predictive of the extent of coronary artery disease (P < 0.02) and inversely predicted the number of normal segments (P < 0.002). Of those variables entered into the regression model, only age was independently predictive of the severity of angiographic coronary artery disease. Apoprotein B levels are not predictive of coronary artery disease severity but do predict independently the extent of involvement of coronary atherosclerosis defined angiographically.