Biological and lifestyle factors, and lipid and lipoprotein levels among Japanese Americans in Seattle and Japanese men in Japan

Abstract

Background. It has been previously shown that Japanese Americans in Seattle have significantly higher cholesterol levels than native Japanese. The present study examines the association of biological and lifestyle factors with plasma lipid and lipoprotein levels among Japanese Americans (JA) and native Japanese (NJ) to determine if these associations are consistent between these high and low cholesterol populations. Methods. Study samples consisted of 710 JA male and 728 JA female volunteers living in the Seattle area and a random sample of 3833 NJ male urban workers who participated in parallel cardiovascular disease screening and lifestyle surveys for 1989-1994. Multiple regression analysis was conducted to examine the association of lifestyle and biological factors with lipid and lipoprotein levels. Results. Alcohol consumption was positively and linearly associated with high density lipoprotein cholesterol (HDL-C) levels and negatively associated with both low density lipoprotein cholesterol (LDL-C) levels and the ratio of total cholesterol (TC)/HDL-C (P < 0.05 to P < 0.001) among JA males and JA females and NJ males. Current smoking habit was observed to be negatively associated with HDL-C levels and positively with TC/HDL-C ratio and log TG levels (logarithmic transformation of triglyceride values) (P < 0.05 to P < 0.001) among all three groups. Body mass index (BMI) was negatively associated with HDL-C levels and positively associated with log TG and TC/HDL-C ratio among all three groups (P < 0.05 to P < 0.001). Moderate alcohol consumption was negatively associated with log TG levels among JA males and females (P < 0.05), whereas heavy alcohol consumption was positively associated with log TG levels in NJ males (P < 0.001). Smoking was positively associated with TC and LDL-C levels (P < 0.05) among JA males, whereas a negative association (P < 0.05) was observed in NJ males. Conclusion. Overall, the fitted models were consistent between JA males and females and NJ males with the exception of smoking on TC and LDL-C. The results suggest that moderate alcohol consumption favourably influences lipid profiles in both high and low cholesterol populations. The results also indicate that light alcohol consumption is associated with decreased triglyceride levels, whereas heavy alcohol consumption is associated with increased triglyceride levels.