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Objectives: We sought to compare the prevalence of coronary atherosclerosis in a cohort of middle-age African American (black) and non-Hispanic Caucasian (white) men and women from a population-based probability sample., Background: Blacks have a higher mortality from coronary heart disease (CHD) than whites, particularly among younger individuals, and yet several studies have reported that coronary atherosclerosis is less prevalent in blacks than in whites. Data from population-based samples comparing coronary atherosclerotic burden between blacks and whites are limited., Methods: The prevalence of coronary atherosclerosis in middle-aged blacks and whites was determined using coronary calcium measured by electron beam computed tomography in 1,289 men and women from a population-based probability sample from Dallas, Texas., Results: The population estimates of the frequency of a positive scan for coronary artery calcium were not statistically different between black and white men (37% vs. 41%, p = 0.36) or between black and white women (29% vs. 23%, p = 0.21). Although the prevalence of most of the coronary risk factors varied significantly between blacks and whites, mean Framingham coronary risk factor scores were identical in black and white men (10 +/- 4) but significantly higher in black women (13 +/- 4) than in white women (12 +/- 4)., Conclusions: Blacks in the general population have a prevalence of coronary atherosclerosis similar to whites. Factors other than coronary atherosclerotic burden, which are not reflected in the Framingham risk score, contribute significantly to the higher CHD mortality rate in blacks.

Circulating osteoprotegerin (OPG) has been shown to be elevated in patients with vascular disease. The role of OPG as a biomarker for atherosclerosis in a large, unselected population is not well known. Plasma OPG levels were measured in 3,386 subjects in the Dallas Heart Study, a multiethnic, population-based probability sample of adults aged 30 to 65 years. Coronary artery calcium (CAC) was measured by electron beam computed tomography. Aortic plaque was assessed by magnetic resonance imaging. Multivariable logistic regression was used to assess associations among OPG, cardiovascular risk factors, CAC, and aortic plaque. Age, female gender, black race, smoking, personal and family history of coronary artery disease (CAD), diabetes mellitus, hyperlipidemia, CAC, and aortic plaque were significantly associated with higher plasma OPG levels (p <0.01) in univariable analyses. The prevalence of CAC and aortic plaque increased across OPG quartiles (p <0.001 for each). An OPG level in the fourth quartile was independently associated with CAC (RR 1.39, 95% confidence interval 1.01 to 1.93) and aortic plaque (RR 1.42, 95% confidence interval 1.09 to 1.86) after adjustment for age, gender, smoking, diabetes, hyperlipidemia, and family history of premature CAD. In conclusion, plasma OPG is independently associated with CAC and aortic plaque in an unselected population, suggesting it may be a novel biomarker for atherosclerosis in humans. [Copyright &y& Elsevier]