Ethnic differences in the formation of small LDL particles in Asians: A comparison of Koreans, Japanese and Mongolians

Background: The presence of small, dense LDL particles has been recognized as an independent risk factor for coronary heart disease (CHD) but is not directly representative of CHD mortality rate beyond any given population. We investigated whether such inconsistency between three Asian ethnic groups might have arisen from anthropometric and metabolic factors. Design: We conducted a cross-sectional survey among adult Koreans (412), Japanese (453) and Mongolians (253). Results: The prevalence of small LDL particles was 36% in the Koreans, 21% in the Japanese and 7% in the Mongolians. Multiple logistic regression analysis revealed plasma triglyceride (TG) levels to be the strongest determinant of small LDL particle size in all three groups, with sex, HDL-cholesterol and non-HDL-C being other ethnic-specific significant determinants. Body mass index (BMI), FFA and insulin resistance were not significant factors in the regression analysis. Of the subjects with low TG levels (< 133 mg dL^-1), 25% of the Koreans and 10% of the Japanese, but no Mongolians, had small LDL particles. Conclusions: Results of the present study suggest that traditionally, high-carbohydrate diets in Korea and Japan possibly contribute to higher TG-levels compared with BMI-matched Mongolians, and to the formation of small LDL particles, even in instances of low TG levels.