Factors associated with high density lipoprotein cholesterol in Japanese and American telephone executives.

The association of plasma high density lipoprotein cholesterol (HDL cholesterol) with several factors was examined in a cross-sectional study of Japanese and American telephone executives. Mean HDL cholesterol levels were similar in both groups of men and were negatively associated with body mass index, smoking, and serum uric acid and positively associated with alcohol and exercise. These associations did not differ between the Japanese and the American men. The mean HDL cholesterol level was 4.2 mg/dl lower in the Japanese than in the American men after adjusting for age, body mass index, alcohol, smoking, exercise, and serum uric acid. The difference in HDL cholesterol between Japanese and American men in this study is inconsistent with the much lower coronary heart disease mortality in Japan and with previous comparison studies of these two populations. Most previous studies have not adjusted for important confounders, but the selective nature of our study groups may have also contributed to this inconsistency. These racial differences in HDL cholesterol may also be due to either genetic or unmeasured environmental and cultural differences. Given the similarity in HDL cholesterol levels between these two groups, our results suggest that HDL cholesterol does not play an important role in the lower coronary heart disease mortality in Japanese men.