The effects of inspiratory muscle training on cardiorespiratory functions in juvenile idiopathic arthritis: A randomized controlled trial

Introduction Although inspiratory muscle training (IMT) has proven effective in adult rheumatic diseases, its impact on juvenile idiopathic arthritis (JIA) remains unexplored. The present study aimed to investigate the effects of IMT in children with JIA. Methods Thirty‐three children (13–18 years) with JIA were divided into two groups as exercise (n = 17) and control (n = 16). The exercise group performed IMT at home daily for 8 weeks. The initial IMT load was set as 60% of maximal inspiratory pressure (PImax) and increased by %10 of the initial load every 2 weeks. The control group received no additional intervention. Forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FVC/FEV1, PImax, and maximal expiratory pressure (PEmax) were evaluated. Peak oxygen consumption (VO2max), metabolic equivalents (METs), and maximal heart rate were measured with cardiopulmonary exercise test. Functional capacity and quality of life were assessed with 6‐min walk distance and Pediatric Quality of Life Inventory 3.0 Arthritis Module. All participants were evaluated at baseline and post‐treatment. Results FVC ( ↑ 0.20 (95% CI: 0.07/0.32) liters), FEV1 ( ↑ 0.14 (95% CI: 0.02/0.25) liters), PImax (↑19.11 (95% CI: 9.52/28.71) cmH2O), PEmax (↑12.41 (95% CI: 3.09/21.72) cmH2O), VO2peak (↑158.29 (95% CI: 63.85/252.73) ml/min), and METs (↑0.92 (95% CI: 0.34/1.49) [ml/kg/min]) significantly improved only in the exercise group (p