Does branched-chain amino acid supplementation improve pulmonary rehabilitation effect in COPD?

BACKGROUND: Muscle wasting is frequent in chronic obstructive lung disease (COPD) and associated with low branched-chain amino acids (BCAA). We hypothesized that BCAA supplementation could potentiate the effect of a pulmonary rehabilitation program (PRP) by inducing muscular change. MATERIALS AND METHODS: Sixty COPD patients (GOLD 2-3) were involved in an ambulatory 4-week PRP either with BCAA oral daily supplementation or placebo daily supplementation in a randomized double-blind design. Maximal exercise test including quadriceps oxygenation measurements, functional exercise test, muscle strength, lung function tests, body composition, dyspnea and quality of life were assessed before and after PRP. RESULTS: Fifty-four patients (64.9 ± 8.3 years) completed the protocol. In both groups, maximal exercise capacity, functional and muscle performances, quality of life and dyspnea were improved after 4-week PRP (p ≤ 0.01). Changes in muscle oxygenation during the maximal exercise and recovery period were not modified after 4-week PRP in BCAA group. Contrarily, in the placebo group the muscle oxygenation kinetic of recovery was slowed down after PRP. CONCLUSION: This study demonstrated that a 4-week PRP with BCAA supplementation is not more beneficial than PRP alone for patients. A longer duration of supplementation or a more precise targeting of patients would need to be investigated to validate an effect on muscle recovery and to demonstrate other beneficial effects.

Multimodal nutritional rehabilitation improves clinical outcomes of malnourished patients with chronic respiratory failure: a randomised controlled trial.

BACKGROUND: In chronic respiratory failure (CRF), body composition strongly predicts survival. METHODS: A prospective randomised controlled trial was undertaken in malnourished patients with CRF to evaluate the effects of 3 months of home rehabilitation on body functioning and composition. 122 patients with CRF on long-term oxygen therapy and/or non-invasive ventilation (mean (SD) age 66 (10) years, 91 men) were included from eight respiratory units; 62 were assigned to home health education (controls) and 60 to multimodal nutritional rehabilitation combining health education, oral nutritional supplements, exercise and oral testosterone for 90 days. The primary endpoint was exercise tolerance assessed by the 6-min walking test (6MWT). Secondary endpoints were body composition, quality of life after 3 months and 15-month survival. RESULTS: Mean (SD) baseline arterial oxygen tension was 7.7 (1.2) kPa, forced expiratory volume in 1 s 31 (13)% predicted, body mass index (BMI) 21.5 (3.9) kg/m2 and fat-free mass index (FFMI) 15.5 (2.4) kg/m2. The intervention had no significant effect on 6MWT. Improvements (treatment effect) were seen in BMI (+0.56 kg/m2, 95% CI 0.18 to 0.95, p=0.004), FFMI (+0.60 kg/m2, 95% CI 0.15 to 1.05, p=0.01), haemoglobin (+9.1 g/l, 95% CI 2.5 to 15.7, p=0.008), peak workload (+7.2 W, 95% CI 3.7 to 10.6, p<0.001), quadriceps isometric force (+28.3 N, 95% CI 7.2 to 49.3, p=0.009), endurance time (+5.9 min, 95% CI 3.1 to 8.8, p<0.001) and, in women, Chronic Respiratory Questionnaire (+16.5 units, 95% CI 5.3 to 27.7, p=0.006). In a multivariate Cox analysis, only rehabilitation in a per-protocol analysis predicted survival (HR 0.27, 95% CI 0.07 to 0.95, p=0.042). CONCLUSIONS: Multimodal nutritional rehabilitation aimed at improving body composition increased exercise tolerance, quality of life in women and survival in compliant patients, supporting its incorporation in the treatment of malnourished patients with CRF. Clinical Trial number NCT00230984.