Effects of Inspiratory Muscle Training in Subjects With Sarcoidosis: A Randomized Controlled Clinical Trial.

BACKGROUND Respiratory muscle weakness occurs in sarcoidosis and is related to decreased exercise capacity, greater fatigue, dyspnea, and lower quality of life in sarcoidosis patients. The effects of inspiratory muscle training in this population have not been comprehensively investigated so far. This study was planned to investigate the effects of inspiratory muscle training on exercise capacity, respiratory and peripheral muscle strength, pulmonary function and diffusing capacity, fatigue, dyspnea, depression, and quality of life in subjects with sarcoidosis. METHODS This was a prospective, randomized, controlled, and double blind study. Fifteen sarcoidosis subjects (treatment group) received inspiratory muscle training at 40% of maximal inspiratory pressure (P(Imax)), and 15 subjects (control group) received sham therapy (5% of P(Imax)) for 6 weeks. Functional and maximal exercise capacity, respiratory and peripheral muscle strength, pulmonary function and diffusing capacity, fatigue, dyspnea, depression, and quality of life were evaluated. RESULTS Functional (P < .001) and maximal exercise capacity (P = .038), respiratory muscle strength (P(Imax) [P < .001] and P(Emax) [P = .001]), severe fatigue (P = .002), and dyspnea perception (P = .02) were statistically significantly improved in the treatment group compared with controls; no significant improvements were observed in pulmonary function and diffusing capacity, peripheral muscle strength, fatigue, depression, and quality of life between groups after inspiratory muscle training. CONCLUSIONS Inspiratory muscle training improves functional and maximal exercise capacity and respiratory muscle strength and decreases severe fatigue and dyspnea perception in subjects with early stages of sarcoidosis. Inspiratory muscle training can be safely and effectively included in rehabilitation programs. (ClinicalTrials.gov registration NCT02270333.).