Abstract
In COPD patients oxidative stress (OS) is a limiting factor of exercise training effects on muscle impairment during pulmonary rehabilitation (PR). Antioxidant supplementation used during PR appeared inappropriate to cope with COPD-related antioxidant deficits. We therefore investigated whether exercise training PR, combined with non-pharmacological antioxidant supplementation (vitamins C and E, zinc, selenium), would have beneficial effects on muscle impairment and exercise capacity.
58 stable COPD patients (61 years; FEV1: 59%predicted) referred for a 4-week PR program, were recruited in a double-blind randomized, placebo-controlled clinical trial. Primary outcome was change in quadriceps endurance (Qend). Secondary outcomes were: quadriceps maximal voluntary contraction (QMVC), exercise capacity (maximal oxygen uptake (Vo2sl), systemic OS markers and muscle fiber cross sectional area (CSA).
Qend was significantly increased in both COPD patient groups. QMVC and VO2sl were improved (+9 and +16%, respectively) exclusively in “PR+antioxidant” group (p=0.01 and p<0.05). The “PR+antioxidant” group showed a significant increase in vitamin E and selenium compared to “PR+placebo” group (p=0.05 and p<0.001, respectively) without differences in vitamin C and lipid peroxidation. Muscle fiber CSA was significantly increased in “PR+antioxidant” group compared to “PR+placebo” group (+17% vs -6% respectively, p<0.05).
In conclusion, this study showed that antioxidant supplementation combining vitamin C, E, zinc and selenium, improves the PR effects on QMVC, Vo2sl and muscle fiber CSA by enhancing antioxidant capacity of COPD patients.
- Copyright ©the authors 2016
