Short period of high-intensity inspiratory muscle training improves inspiratory muscle strength in patients with chronic kidney disease on hemodialysis: a randomized controlled trial

Abstract

Background: Chronic kidney disease is a complex disease that impacts multiple organs and systems (including musculoskeletal and cardiorespiratory) leading to reduction of functional capacity.

Objective: The aim of this study was to investigate the effect of a short period of high intensity inspiratory muscle training on maximum inspiratory pressure, functional capacity and endothelial function of chronic kidney disease patients on hemodialysis.

Methods: This randomized controlled trial enrolled 25 patients who were allocated into two groups: intervention (IMTG=14) and control (CG=11) groups. Intervention patients received the exercise protocol over a period of 5 weeks, 6 times per week, with each session consisting of 5 sets of 10 repetitions with an initial load of 50% progressing to 70% of maximum inspiratory pressure , measured weekly. The primary outcome was inspiratory muscle strength and the secondary outcomes were functional capacity and endothelial function evaluated before and after the training protocol.

Results: The inspiratory muscle training induced a marked improvement in maximum inspiratory pressure which was evident after the training period (mean difference 19.0cmH₂O - 95%CI 0.4-37.5; IMTG: 102±25.7cmH₂O vs CG: 83±19.2; p=0.046). The magnitude of maximum inspiratory pressure improvement was 33.5% at the end of the protocol for the IMTG. Functional capacity and endothelial function did not vary between or within groups.

Conclusion: A short period of high-intensity inspiratory muscle training for five weeks was able to improve inspiratory muscle strength of chronic kidney disease patients on hemodialysis (ClinicalTrials.gov registration NCT03082404).

Keywords: Chronic kidney disease; Kidney dialysis; Rehabilitation; Respiratory exercises; Respiratory muscle.