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.

BACKGROUND: Lipoprotein particle levels and size distributions differ by race. As a group, blacks have less coronary artery calcification (CAC) than whites. We evaluated whether racial differences in CAC are explained by differences in lipoprotein levels and particle sizes.
METHODS: A total of 721 blacks and 988 whites underwent measurement of fasting lipoprotein levels and particle sizes. There were 608 subjects who had CAC quantified by electron beam computed tomography. Distributions and interrelationships among lipoprotein levels, particle sizes, and CAC were evaluated by race and sex.
RESULTS: Blacks had nominally higher adjusted high-density lipoprotein cholesterol levels (men, 51 vs 50 mg/dL; women, 63 vs 61 mg/dL; P = .05), lower intermediate-density lipoprotein cholesterol levels (women only, 17 vs 18 mg/dL; P = .02), and significantly lower triglyceride levels (men, 116 vs 138 mg/dL; women, 103 vs 136 mg/dL; P < .0001) than whites. Adjusted small dense low-density lipoprotein 3 particle levels were significantly lower (P < .0001) in black men (47 vs 53 mg/dL) and black women (43 vs 48 mg/dL) compared with white men and women, respectively. Black race was associated with a 48% lower adjusted odds of moderate or significant CAC (odds ratio, 0.52; 95% confidence interval, 0.34-0.80). 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.