Oxygen supplementation increases the total work and muscle damage markers but reduces the inflammatory response in COPD patients

Abstract

IntroductionOxygen supplementation (O2-Suppl) is recommended for pulmonary rehabilitation with higher exercise intensities. However, high-intensity exercise tends toward muscle damage and a greater inflammatory response. We aimed to investigate the effect of O2-Suppl during exercise test (EET) on CRP level and muscle damage (CPK, LDH, lactate) in non-hypoxemic COPD patients. MethodsEleven non-depleted patients with COPD (FEV1 65.5 ± 4.3 %) performed two EET (room-air or O2-Suppl-100 %), through a blind, randomized, and placebo-controlled crossover design. CPK, LDH and CRP were measured before, immediately after and 24 h after EET. ResultsExercise time was higher with O2-Suppl (49.9 ± 37.3 %; p = 0.001) and increases in CPK and LDH were observed compared to basal values in the O2-Suppl (28.4UI/L and 28.3 UI/L). The O2-Suppl protocol resulted in a lower increase in CRP (92.1 ± 112.4 % vs. 400.1 ± 384.9 %; p = 0.003). ConclusionsO2-Suppl increases exercise-tolerance, resulting in increased muscle injury markers in COPD. However, oxygen supplementation attenuates the inflammatory response, even upon increased physical exercise.