Discordance between apolipoprotein B and low-density lipoprotein cholesterol and progression of coronary artery calcification in middle age

Abstract

Background: A high level of apolipoprotein B (apoB) is associated with incident coronary artery disease (CAD) when low-density lipoprotein cholesterol (LDL-C) level is discordantly low or concordantly high. However, data on the relationship of apoB with subclinical measure of CAD are limited. Methods and Results: A total of 14,205 men (mean age 41.0 years) who were free of cardiovascular disease at baseline and who underwent a health checkup exam, including measurement of coronary artery calcium (CAC), were studied. Of the study group, 2,773 participants (19.5%) had CAC at baseline, and CAC progression was observed in 2,550 (18.0%). The multivariate-adjusted CAC score ratios (95% confidence interval) comparing discordantly high apoB/low LDL-C and concordantly high apoB/high LDL-C with concordantly low apoB/low LDL-C were 1.51 (0.98-2.32) and 2.70 (2.19-3.33), respectively. The corresponding relative risks for CAC progression were 1.26 (1.02-1.56) and 1.49 (1.34-1.66), respectively. These associations did not change appreciably after adjustment for insulin resistance and subclinical inflammation. Conclusions: Discordant analysis showed that a high apoB level was strongly associated with prevalence and progression of CAC independent of LDL-C in a large cohort of healthy adults. The present study results highlighted the importance of an apoB measure as a potential target for primary prevention of coronary atherosclerosis in healthy adults.