Effects of chronic obstructive pulmonary disease stage on muscle oxygenation during exercise

Aims: The aim of this study was to investigate peripheral muscle oxygenation in patients with chronic obstructive pulmonary disease (COPD) at rest, during submaximal exercise, and during recovery, and to determine the effects of disease stage on peripheral muscle oxygenation. Methods: Of the 35 stable COPD patients (62.49±8.45 years), 18 patients in GOLD 1 and 2 were assigned to Group 1 and 17 patients in GOLD 3 and 4 were assigned to Group 2. Dyspnea perception of the patients was evaluated with the Modified Medical Research Council (mMRC) Dyspnea Scale, severity of the disease affecting daily life was evaluated with the COPD Assessment Test (CAT-COPD Assessment Test), respiratory function was evaluated with the Pulmonary Function Test, and quadriceps muscle strength was evaluated with a manual muscle testing device. Muscle oxygenation of the patients was measured with Near-infrared spectroscopy (NIRS) for 5 minutes at rest, 6 minutes during the 6-Minute Walk Test (6-MWT), and 5 minutes during recovery after the end of the test. The results of the two groups were compared. Results: Intragroup comparisons of muscle oxygenation at rest, during 6-MWT and during recovery; in Group 1, there was a statistically significant decrease between resting SmO2 mean and test SmO2 mean (p=0.001), a increase between test SmO2 mean and recovery SmO2 mean (p