Effects of respiratory muscle training in patients with interstitial lung diseases: Systematic review

Background: Inspiratory muscle training (IMT) is a component of the pulmonary rehabilitation(PR) program for patients with chronic lung disease. Objectives: This systematic review aimed to determine the effects of IMT on respiratory muscle strength, functional exercise capacity, dyspnea, quality of life (QoL), lung functions, and diffusion capacity (DLCO) in patients with Interstitial Lung Disease (ILD). Methods: This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Publications from inception to 2025 were searched using MeSH terms across six databases. The titles and abstracts of the studies were screened via Rayyan-AI software by two independent authors. After full-text screening, randomized controlled trials that met the inclusion criteria were included. Results: According to mesh terms, 9020 articles were identified at baseline. After the screening, duplicate articles removed, and three randomized controlled trials were included. Finally, A total of 109 patients with ILD were included.Although only 3 studies were included in this systematic review, the evidence level for IMT on functional exercise capacity, dyspnea and inspiratory muscle strength was strong and no effect on lung functions and DLCO in patients with ILD. Additionally, there is conflicting evidence regarding the improvement in QoL, with limited evidence of the progress in expiratory muscle strength. Conclusion: Considering the small number of articles included in this systematic review, IMT programs lasting ≥6 weeks appear beneficial and safe for improving respiratory muscle strength, dyspnea, and functional exercise capacity. However, more rigorous studies are needed to confirm these benefits.