Effects of Branched-Chain Amino Acids on Skeletal Muscle, Glycemic Control, and Neuropsychological Performance in Elderly Persons with Type 2 Diabetes Mellitus: An Exploratory Randomized Controlled Trial
Takaaki Matsuda,
Hiroaki Suzuki,
Yoko Sugano,
Yasuhiro Suzuki,
Daisuke Yamanaka,
Risa Araki,
Naoya Yahagi,
Motohiro Sekiya,
Yasushi Kawakami,
Yoshinori Osaki,
Hitoshi Iwasaki,
Koichi Hashimoto,
Shin-Ichiro Takahashi,
Yasushi Hada,
Hitoshi Shimano
Affiliations
Takaaki Matsuda
Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
Hiroaki Suzuki
Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
Yoko Sugano
Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
Yasuhiro Suzuki
Department of Rehabilitation Medicine, University of Tsukuba Hospital, Tsukuba 305-8576, Japan
Daisuke Yamanaka
Laboratory of Food and Physiological Models, Department of Veterinary Medical Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 133-8657, Japan
Risa Araki
Department of Clinical and Translational Research Methodology, Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
Naoya Yahagi
Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
Motohiro Sekiya
Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
Yasushi Kawakami
Department of Laboratory Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
Yoshinori Osaki
Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
Hitoshi Iwasaki
Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
Koichi Hashimoto
Department of Clinical and Translational Research Methodology, Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
Shin-Ichiro Takahashi
Department of Animal Resource Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
Yasushi Hada
Department of Rehabilitation Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
Hitoshi Shimano
Department of Internal Medicine (Endocrinology and Metabolism), Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Japan
Although branched-chain amino acids (BCAA) are known to stimulate myofibrillar protein synthesis and affect insulin signaling and kynurenine metabolism (the latter being a metabolite of tryptophan associated with depression and dementia), the effects of BCAA supplementation on type 2 diabetes (T2D) are not clear. Therefore, a 24-week, prospective randomized open blinded-endpoint trial was conducted to evaluate the effects of supplementation of 8 g of BCAA or 7.5 g of soy protein on skeletal muscle and glycemic control as well as adverse events in elderly individuals with T2D. Thirty-six participants were randomly assigned to the BCAA group (n = 21) and the soy protein group (n = 15). Skeletal muscle mass and HbA1c, which were primary endpoints, did not change over time or differ between groups. However, knee extension muscle strength was significantly increased in the soy protein group and showed a tendency to increase in the BCAA group. Homeostasis model assessment for insulin resistance did not significantly change during the trial. Depressive symptoms were significantly improved in the BCAA group but the difference between groups was not significant. Results suggested that BCAA supplementation may not affect skeletal muscle mass and glycemic control and may improve depressive symptoms in elderly individuals with T2D.