The effects of bolus supplementation of branched-chain amino acids on skeletal muscle mass, strength, and function in patients with rheumatic disorders during glucocorticoid treatment

Abstract

Objectives: To test the effects of bolus supplementation of branched-chain amino acids (BCAA) on skeletal muscle mass, strength, and function in patients with rheumatic disorders taking glucocorticoid (GC).

Methods: Patients with rheumatic disorders treated with prednisolone (≥10 mg/day) were randomized to ingest additional daily 12 g of BCAA (n = 9) or not (n = 9) for 12 weeks. At baseline, and 4, 8, and 12 weeks, they underwent bioelectrical impedance analysis, muscle strength and functional tests, and computed tomography analysis for cross-sectional area of mid-thigh muscle.

Results: Disease activities of the patients were well controlled and daily GC dose was similarly reduced in both groups. Limb muscle mass was recovered in both groups. Whole-body muscle mass and muscle strength and functional mobility were increased only in BCAA (+) group. The effects of BCAA supplementation on recovering skeletal muscle mass were prominent in particular muscles including biceps femoris muscle.

Conclusions: This trial is the first-in-man clinical trial to demonstrate that BCAA supplementation might be safe and, at least in part, improve skeletal muscle mass, strength, and function in patients with rheumatic disorders treated with GC.

Keywords:

• Branched-chain amino acids
• Glucocorticoids
• mTOR
• Rheumatic disorders
• Skeletal muscle atrophy

Acknowledgments

The authors would like to thank the patients who were involved in this study. We also thank all members of our department and Center for Translational Research, IMSUT Hospital.

Conflict of interest

None. This work was supported by JSPS KAKENHI (Grants-in-Aid for Scientific Research (B) and Challenging Exploratory Research to Hirotoshi Tanaka (24390236, 16H05330 and 15K12695), for Scientific Research (C) to Noritada Yoshikawa (25461469 and 16K09230) and to Noriaki Shimizu (26461375), for Encouragement of Scientist to Akiko Kuribara-Souta (16H00627) and for Research Activity Start-up to Hiroshi Kobayashi (25893051)), and by grants from the Ministry of Health, Labour and Welfare to Hirotoshi Tanaka, IMSUT Joint Research Project to Hirotoshi Tanaka and Noriaki Shimizu (139). This work was also supported by grants from SENSHIN Medical Research Foundation, Takeda Science Foundation, the Nakatomi Foundation, and Suzuken Memorial Foundation to Noritada Yoshikawa, and from Takeda Science Foundation and Mochida Memorial Foundation for Medical and Pharmaceutical Research to Noriaki Shimizu. These funds had no control over the interpretation, writing, or publication of this work.