Inspiratory muscle training (IMT) in interstitial lung disease (ILD) - A pilot study

Abstract

Introduction: The 2013 ATS/ERS guidelines on Pulmonary Rehabilitation suggest that IMT confers significant improvements in various outcomes in chronic obstructive pulmonary disease (COPD). However, the effects of IMT in ILD are currently unknown. Objective: To investigate the effect of incremental high-intensity (H)-IMT on exercise capacity, dyspnoea, inspiratory muscle function and health-related quality of life in ILD patients Methods: A single-blind randomised controlled study recruited 17 patients with ILD from St George9s Hospital chest clinic, London. 9 patients (intervention group); median (IQR) DLco predicted 44 [28, 45] % underwent H-IMT; exercised at 60% of sustained maximal inspiratory pressure (SMIP); 8 patients (control group) median (IQR) DLco 39.5 [24, 60] % underwent low intensity IMT (S-IMT); exercised at 15% of SMIP. This was a supervised, 8-week, biweekly, outpatient programme. Primary outcome was the six minute walk test (6MWT); secondary outcomes included: quality of life (SGRQ-I), dyspnoea: (Borg and Dyspnoea-12), maximal inspiratory pressure (MIP) and sniff nasal inspiratory pressure (Sniff-P). Results: 14 patients completed the study. Patients under H-IMT exhibited significantly higher MIP compared to S-IMT patients (p=0.043). There were no significant between-group differences in the other parameters. H-IMT improved significantly on 6MWT, MIP, Sniff-P, and SGRQ-I. S-IMT, improved significantly on 6MWT, Borg and D-12. Conclusion: Results suggest that H-IMT represents a promising exercise training modality, which improves inspiratory muscle function in ILD patients. Larger studies are required to investigate the effect of IMT on exercise capacity, QoL and dyspnoea.