Inspiratory Muscle Training in the Severity of Obstructive Sleep Apnea, Sleep Quality and Excessive Daytime Sleepiness: A Placebo-Controlled, Randomized Trial

Purpose: Exercise programs have been considered as an adjuvant treatment in obstructive sleep apnea (OSA). However, few studies have focused on the effects of the inspiratory muscle training (IMT) in reducing the severity and the symptoms of OSA.

Patients And Methods: A randomized controlled trial was conducted and approved by the local Ethics Committee. All subjects signed the informed consent form and were randomized into 2 groups: a) IMT group (n = 8), 8 weeks of IMT with 75% of maximal inspiratory pressure (MIP) and b) placebo group (n = 8): subjects performed IMT without load.

Results: IMT group showed reduction in the apnea-hypopnea index (AHI) (p = 0.01), in the Berlin questionnaire score (p = 0.001) and an increase in inspiratory muscle strength (p = 0.018). IMT group demonstrated a reduction in the AHI (31.7 ± 15.9 events/h vs 29.9 ± 15.8 events/h; p <0.001), in the Berlin questionnaire scores (2.6 ± 0.5 vs 1.2 ± 0.5; p = 0.016), Pittsburgh Sleep Quality Index (PSQI) score (7.2 ± 3.6 vs 3.7 ± 1.3; p = 0.008), in the Epworth Sleepiness Scale (ESS) (12.5 ± 4.0 vs 7.7 ± 3.0; p = 0.008) and increase in MIP (83.6 ± 26.5 cmHO and 127.9 ± 32.5 cmHO; p = 0.010).

Conclusion: The IMT promotes discrete changes in the AHI and improves sleep quality and excessive daytime sleepiness in OSA. Moreover, IMT is a cheap, useful and simple home-based training program and can be considered as an adjunct therapy for OSA patients.