Recent researches have revealed an association between circulating branched-chain acid (BCAA) and obesity and insulin resistance. In addition, experiments using rodents have revealed that adiponectin (APN) regulates the systemic BCAA level by affecting its catabolism. However, the influence of glucose intolerance on the relationship between BCAA and insulin sensitivity (IS) and between APN and BCAA in humans is unknown. Hence, we aimed to investigate these associations in individuals with varying degrees of glucose tolerance. Based on the data of 75g OGTT in 75 Japanese individuals without diabetic medication [age:65±11 (mean±SD); BMI: 24.9±3.8], individuals were classified into the normal, impaired glucose tolerance, and diabetes (DM) group (n=25 in each group). Matsuda index (MI) was calculated as an index of IS. Normally-distributed loge-transformed (ln-) values were used for MI and APN. Fasting BCAA was assayed using an enzymatic method. In analysis of total individuals using stepwise regression analysis, BMI (β=-0.477, p<0.0001) and BCAA (β=-0.243, p=0.0195) are significant factors for predicting ln-MI. Furthermore, BMI, ln-APN, age, and sex are significant factors for predicting BCAA. In multiple regression analysis, using ln-MI as a dependent variable and BMI and BCAA as independent variables in each group, BCAA was negatively and significantly correlated with ln-MI only in the DM group, but not in the other groups [DM: β of BMI =-0.325, β of BCAA =-0.465 (p=0.02), R2=0.509]. In multiple regression analysis, using BCAA as a dependent variable and BMI and ln-APN as independent variables in each group, ln-APN was negatively and significantly correlated with BCAA in all the groups. In conclusion, BCAA was negatively correlated with IS independent of BMI, especially in individuals with DM. APN was negatively correlated with BCAA, independent of glucose tolerance.
E. Amano: None. K. Yoshimura: None. S. Funakoshi: None. S. Hirano: None. S. Ohmi: None. Y. Terada: None. S. Fujimoto: None.