UCLA

Background/objectives

Higher volumes of ectopic cardiovascular fat (ECF) are associated with greater risk of coronary heart disease (CHD). Identifying factors that are associated with ECF volumes may lead to new preventive efforts to reduce risk of CHD. Significant racial/ethnic differences exist for overall and central adiposity measures, which are known to be associated with ECF volumes. Whether racial/ethnic differences also exist for ECF volumes and their associations with these adiposity measures remain unclear.

Subjects/methods

Body mass index (BMI), computerized tomography-measured ECF volumes (epicardial, pericardial and their summation) and visceral adipose tissue (VAT) were examined in a community-based sample of 1199 middle-aged men (24.2% Caucasians, 7.0% African-Americans, 23.6% Japanese-Americans, 22.0% Japanese, 23.2% Koreans).

Results

Significant racial/ethnic differences existed in ECF volumes and their relationships with BMI and VAT. ECF volumes were the highest among Japanese-Americans and the lowest among African-Americans. The associations of BMI and VAT with ECF differed by racial/ethnic groups. Compared with Caucasians, for each 1-unit increase in BMI, African-Americans had lower, whereas Koreans had higher increases in ECF volumes (P-values<0.05 for both). Meanwhile, compared with Caucasians, for each 1-unit increase in log-transformed VAT, African-Americans, Japanese-Americans and Japanese had similar increases, whereas Koreans had a lower increase in ECF volumes (P-value<0.05).

Conclusions

Racial/ethnic groups differed in their propensity to accumulate ECF at increasing level of overall and central adiposity. Future studies should evaluate whether reducing central adiposity or overall weight will decrease ECF volumes more in certain racial/ethnic groups. Evaluating these questions might help in designing race-specific prevention strategy of CHD risk associated with higher ECF.