Does inspiratory muscle training (IMT) improve sleep quality in adult patients with obstructive sleep apnea?

Objective: The objective of this selective EBM review is to determine whether or not inspiratory muscle training (IMT) improves sleep quality in adult patients with obstructive sleep apnea. Study Design: A systematic review of three randomized controlled trials (RCT) published between 2018 and 2020. Data Sources: All articles were published in peer reviewed journals and obtained using PubMed, AMED, CINAHL Plus, MEDLINE databases. The studies were chosen based on their relevance to the clinical question. Outcome Measured: The outcome measured in all three studies was subjective improvement in sleep quality. The participants overall sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). The sum of the scores in each component totals to a minimum score of 0 and a maximum score of 21. A score of 0-4 points indicates good quality sleep, while a score of \u3e 5 points indicates poor sleep. All three studies compared the pre-treatment and post-treatment PSQI scores as a mean change from baseline. Results: In the RCT conducted by Nóbrega-Júnior et al., IMT led to an improvement in sleep quality compared to the control group. The mean change from baseline for the IMT group was 3.5, while the mean change from baseline for the placebo group was 0.7. The p-value was calculated to be 0.01, making this study statistically significant with a large treatment effect. In the RCT by Souza et al., there was a mean change from baseline of 2.9 for the IMT group, and 0.9 for the placebo group. There was a calculated p-value of 0.02. This study was shown to be statistically significant with a large treatment effect. In the RCT conducted by Vranish et al., the mean change from baseline for the IMT group was 4.0 and unchanged for the placebo group. The p-value was 0.001 and the study was found to be statistically significant with a large treatment effect. Conclusion: The results of these three studies demonstrated that IMT led to a significant improvement in sleep quality as measured by the PSQI. This suggests IMT is an effective and useful method of treatment for adult obstructive sleep apnea patients. Further studies should explore a larger sample size that compares various intensities of treatment to determine optimal therapy