Inspiratory Muscle Training (IMT) Combined with Continuous Positive Airway Pressure (CPAP) versus CPAP Alone: A Randomized Clinical Trial in Patients with Obstructive Sleep Apnea

Objective Obstructive sleep apnea, as a disorder that affects various aspects of patients’ lives, has a considerable prevalence worldwide. Therefore, improving its complications and enhancing the quality of life of these patients are of great importance. Accordingly, the present study aimed to compare the effects of using CPAP combined with IMT versus CPAP alone in these patient. Methods The present study was a single-blind randomized clinical trial conducted on 48 patients with obstructive sleep apnea, who were randomly assigned into two groups of 24 participants each. In the intervention group, a combination of inspiratory muscle training (IMT) and continuous positive airway pressure (CPAP) was applied, whereas the control group received CPAP alone as the standard treatment. The intervention was carried out over 12 weeks, with two 25-minute sessions per week. Apnea severity, daytime sleepiness, and quality of life were assessed using validated questionnaires. Data were analyzed using SPSS version 16. The Chi-square and Fisher’s exact tests were employed for qualitative variables, while the paired t-test, Wilcoxon test, and analysis of covariance (ANCOVA) were used for quantitative variables. A significance level of p < 0.05 was considered statistically significant. Results The results showed that after the intervention, the mean score of obstructive sleep apnea risk was significantly lower in the CPAP + IMT group compared with the CPAP group (P = 0.013, effect size = 0.35). Daytime sleepiness also showed a remarkable reduction in the combined intervention group (P < 0.0001, effect size = 0.35), and all patients in this group fell within the normal range after the intervention. Moreover, quality of life significantly improved in the CPAP + IMT group compared to the CPAP group (P < 0.05). Conclusion The IMT tool can be used, based on the results of the present study, in patients with obstructive sleep apnea to reduce disease complications and also to improve their quality of life. Therefore, it is recommended that specialists incorporate the findings of this study into the treatment programs of these patients, considering the simple method of implementation, ease of training, and accessibility. Clinical Trial Registration Number : IRCT20250127064538N1 (Registered on 2025-03-01).