Association between plasma concentrations of branched-chain amino acids and adipokines in Japanese adults without diabetes.

Previous studies have consistently reported an association between circulating levels of branched-chain amino acids (BCAAs) or adipokines and insulin resistance; however, the association between BCAA and adipokine levels remains to be clarified. In this cross-sectional study involving 678 participants (435 men) without diabetes, plasma BCAA (valine, leucine, and isoleucine), adipokine (total and high molecular weight [HMW] adiponectin, leptin, and tumor necrosis factor-α [TNF-α]) concentrations, and an updated homeostasis model assessment of insulin resistance (HOMA2-IR) were measured. The association between the concentrations of total BCAAs and adipokines was adjusted for confounding factors, including body mass index. For the lowest and highest BCAA quartiles, the adjusted geometric mean levels of HMW adiponectin were, respectively, 1.51 and 0.91 μg/mL, in men (P for trend < 0.0001); 3.61 and 2.29 μg/mL, in women (P = 0.0005). The corresponding geometric mean levels for leptin were 1681 and 2620 pg/mL, in men (P = 0.003), and 4270 and 6510 pg/mL, in women (P = 0.003). Those for HOMA2-IR were 0.89 and 1.11, in men (P < 0.0001), and 0.79 and 0.96, in women (P < 0.0001); no significant association was found with TNF-α. These results suggest significant associations between BCAA concentrations and those for adiponectin, leptin and HOMA2-IR in individuals without diabetes.