Does a supplementation in branch amino acid improve pulmonary rehabilitation effect in COPD?

Background: Chronic obstructive lung disease (COPD) affects many organs or functions that play an important role in disease progression. Muscle wasting is frequent and associated with low branched-chain amino acids (BCAA). We hypothesized that BCAA supplementation could potentiate the effect of pulmonary rehabilitation program (PRP) and improve exercise capacity by inducing muscular change. Methods: Sixty COPD patients (GOLD 2-3) were involved in an ambulatory 4-week PRP, with BCAA oral daily supplementation (4.3g/daily dose: 25.83% valine, 27.05% isoleucin and 47.12% leucine) or a placebo in a double-blind design. Cardiopulmonary exercise test (Médisoft, Exp’air) including a measurement of quadriceps oxygenation (Oxymon Mk III, Artinis), 6 min walk test, quadriceps muscle strength (Koch bank, Salter dynamometer), lung function, body composition (BioparthΩm, Z Metrix®), dyspnea (mMRC scale) and quality of life (VQ11) were assessed before and after PRP Results: 54 patients (64,9 ± 8,3 years) completed the protocol. In both groups, maximal exercise capacity, functional and muscle performances were increased after 4 weeks PRP (p<0.01), as well as quality of life and dyspnea. However, changes were not more important in the BCAA supplemented group. Changes in quadriceps oxygenation in response to exercise were not modified after PRP, however in BCAA group, p values ≤ 0.07 were obtained at maximal exercise for oxygenated and deoxygenated haemoglobin muscle concentration. Conclusion: This study demonstrated that a 4-week PRP provides a large panel of improvements in COPD patients but that BCAA supplementation does not give more benefit that pulmonary rehabilitation alone.