Ethnic differences in the relationship between pericardial adipose tissue and coronary artery calcified plaque: African-American-diabetes heart study.

BACKGROUND: Calcified atherosclerotic plaque (CP) is less prevalent and less severe in African-Americans (AA), relative to European Americans (EA). Because pericardial adipose tissue (PAT) is associated with CP in the neighboring coronary arteries, we explored ethnic-specific relationships between PAT and CP.
METHODS: PAT volume and coronary and aortic CP were measured in 561 EA and 575 AA subjects with type 2 diabetes using single and multidetector computed tomography. Generalized estimating equations with exchangeable correlation and the sandwich estimator of the variance were used to test for associations between PAT and CP.
RESULTS: Mean (sd) ages of AA and EA participants were 56.7 (9.5) and 62.0 (8.9) yr, respectively; diabetes duration was 10.5 (8.1) and 10.1 (7.3) yr; and PAT volume was 86.9 (38.6) and 131.7 (55.3) cm3/45 mm. In AA and EA participants, respectively, mean (sd) coronary CP mass scores were 803 (1,889) and 1,465 (2,847) mg calcium; and aortic CP, 5,407 (10,651) and 10,090 (15,087) mg calcium. Adjusting for age, gender, body mass index, blood pressure, height, smoking, lipid-lowering medications, C-reactive protein, albuminuria, high-density lipoprotein-cholesterol, and triglycerides, parameter estimates for the relationship between PAT and log(coronary CP+1) were 0.012 in AA (P<0.0001) and 0.003 (P=0.24) in EA, with a significant ethnic difference (P=0.019). No significant relationships or ethnic differences were observed between PAT and aortic CP (P=0.24, fully adjusted model).
CONCLUSIONS: Pericardial adiposity is strongly associated with coronary atherosclerosis in AA with type 2 diabetes. Novel cardiovascular disease risk factors such as PAT may contribute to ethnic disparities in susceptibility to development of coronary atherosclerosis.