Adipogenic risk factor differences between Korean and white adults--potential role of plasma free fatty acid and adiponectin.

Asian adults are at greater risk for metabolic abnormalities (insulin resistance, dyslipidemia) at the same body mass index (BMI) than are whites. Elevated free fatty acids (FFA) and decreased adiponectin are linked with these same metabolic abnormalities. We tested the hypothesis that fasting plasma FFA are greater and adiponectin concentrations are lower in Korean than white adults matched for age, sex, and BMI. Plasma FFA and adiponectin concentrations were analyzed using a microfluorometric assay and radioimmunoassay, respectively. Fasting plasma FFA concentrations were not different (P = .51) between Korean and white subjects (208 [183-232] vs 215 [168-262] mumol/L, median and 95% confidence interval). Despite similar body composition in the 2 groups, the plasma adiponectin concentrations in Koreans were significantly lower than those in whites in men, women, and total subgroups (adjusted mean +/- SEM: 4.9 +/- 0.8 vs 9.1 +/- 0.8 microg/mL, P = .004; 8.9 +/- 1.0 vs 13.2 +/- 1.0 microg/mL, P = .006; and 6.5 +/- 0.6 vs 11.1 +/- 0.6 microg/mL, P <or= .001, respectively) after adjustment for differences in height, weight, and fat-free mass as covariates. Men had lower plasma adiponectin concentrations than women in both Korean (P = .041) and Western adults (P < .001). Plasma adiponectin levels are lower in Korean than age-, sex-, and body mass index-matched white adults, whereas fasting plasma FFA are not different. To the extent that adipogenic factors account for ethnic differences in metabolic disease risk, our data suggest that differences in the regulation of adiponectin may predispose toward greater metabolic abnormalities in Asians than whites at comparable BMI levels.