Abstract 1193: Racial Differences in Coronary Artery Calcification Are Not Attributed to Differences in Lipoprotein Particle Sizes: The Heart Strategies Concentrating On Risk Evaluation (Heart SCORE) Study
Introduction: Lipoprotein particle levels and size distributions differ by race. As a group, blacks have less coronary artery calcification (CAC) than whites. However, the contribution of race-related differences in lipoprotein profiles to race-related differences in CAC is uncertain.
Hypothesis: We evaluated whether racial differences in CAC are explained by differences in lipoprotein levels and particle sizes.
Methods: 721 blacks and 988 whites underwent measurement of fasting lipoprotein levels and particle sizes. 608 subjects had CAC quantified by electron beam computed tomography. Distributions and interrelationships among lipoprotein levels, particle sizes, and CAC were evaluated by race and gender.
Results: Blacks had modestly higher HDL cholesterol levels (males: 50.9 vs. 49.7 mg/dl; females: 62.7 vs. 61.2 mg/dl, p=0.05), lower IDL levels (females only: 16.9 vs. 18.3 mg/dl, p=0.02), and significantly lower triglyceride levels (males: 116.4 vs. 138.4 mg/dl; females: 102.7 vs. 135.7 mg/dl, p= 0.0001) than whites. Small dense LDL3 particle levels were significantly lower (p<0.0001) in black males (46.4+20.3 vs. 53.1+17.7 mg/dl) and black females (4.3+19.8 vs. 47.6+20.4 mg/dl) compared to white males and females, respectively. Black race was associated with a 46% lower adjusted odds of moderate or significant CAC (odds ratio=0.54, 95% confidence interval: 0.36 – 0.8., p<0.002). However, this strong association between race and CAC was independent of lipoprotein levels and particle sizes.
Conclusions: Blacks have less CAC and more favorable lipoprotein profiles than whites. Racial differences in CAC are not attributable to differences in lipoprotein particle sizes. Future studies of mechanisms of race-related differences in CAC may enhance understanding of the pathophysiology of racial differences in cardiovascular disease.