Pos0585-hpr effectiveness of inspiratory muscle training on aerobic capacity, respiratory functions and respiratory muscle strength in children with juvenile idiopathic arthritis: a single-blinded randomised controlled trial

Background Children with juvenile idiopathic arthritis (JIA) may present lower aerobic capacity, lung volumes, and respiratory muscle strength compared to their healthy peers [1]. Objectives This study aimed to investigate the effectiveness of inspiratory muscle training (IMT) on aerobic capacity, lung volumes, respiratory muscle strength, functional capacity, and quality of life in children with JIA. Methods Thirty-three children with JIA who were on the same biologic disease modifying anti-rheumatic drugs for at least three months were included and divided into two groups as exercise group (n=17, mean age: 15.1±2.2 years, 12 male) and control group (n=16, mean age: 15.7±1.6 years, 11 male). Exercise group performed IMT daily for eight weeks. Initial IMT load was set as the 60% of maximal inspiratory pressure (PI max ) and was increased by %10 every two weeks. Control group received no additional intervention. Forced vital capacity (FVC), forced expiratory volume in one second (FEV 1 ), FVC/FEV 1 ratio, PI max , and maximal expiratory pressure (PE max ) were evaluated using a portable pulmonary function test device (Cosmed Pony FX, Rome, Italy). Participants performed a maximal Cardiopulmonary Exercise Test to measure maximal oxygen consumption (VO 2peak ), metabolic equivalent (MET) and maximal heart rate. Six-minute walking distance (6MWD) was used to evaluate lower-extremity related functional capacity. The Pediatric Quality of Life Inventory (PedsQL) 3.0 Arthritis Module was used to evaluate the quality of life. Participants were evaluated at baseline and at the end of eight weeks. Results The groups were similar at baseline. FVC, FEV 1 , PI max , PE max , VO 2peak , and MET significantly improved at the end of eight weeks in the exercise group (p<0.05), while no significant differences were observed in the control group (p>0.05). The difference over time in FVC, FEV 1 , PI max , VO 2peak , and MET were significantly higher in the exercise group compared to control group (p<0.05, Table 1). No other between group differences were detected (p>0.05). Conclusion IMT seems beneficial for improving respiratory functions in children with JIA. References [1]Alkady EA, Helmy HA, Mohamed-Hussein AA. Assessment of cardiac and pulmonary function in children with juvenile idiopathic arthritis. Rheumatol Int 2012;32(1):39-46. doi: 10.1007/s00296-010-1548-5. Table 1. Comparison of change-over-time values between groups Mean Differences (95 %CI) p* ES Exercise Group (n=17) Control Group (n=16) Lung Volumes FVC (l) 0.20 (0.07/0.32) -0.01 (-0.11/0.09) 0.010 0.96 FEV 1 (l) 0.14 (0.02/0.25) 0.02 (-0.11/0.14) 0.124 - FEV 1 /FVC (%) 0.16 (-1.96/2.30) 1.74 (-1.50/4.98) 0.389 - Respiratory Muscle Strength PI max (cmH 2 O) 19.11 (9.52/28.71) 1.56 (-3.37/6.50) 0.002 1.18 PE max (cmH 2 O) 12.41 (3.09/21.72) 5.06 (-1.55/11.68) 0.187 - Cardiopulmonary Exercise Test VO 2peak (ml/min) 158.2 (63.8/252.7) 16.8 (-68.9/102.6) 0.026 0.81 VO 2peak /Body weight 3.28 (1.14/5.42) 0.33 (-1.47/2.14) 0.034 0.78 METs (ml/kg/min) 0.92 (0.34/1.49) 0.06 (-0.35/0.48) 0.015 0.88 HR peak (pulse/min) 3.47 (0.17/6.76) 1.18 (-3.0/5.37) 0.367 - HRR (pulse) -3.47 (-6.76/-0.17) -1.18 (-5.37/3.0) 0.367 - VO 2peak /HR peak 0.59 (0.18/1.00) -0.02 (-0.37/0.34) 0.024 0.82 Lower Extremity Related Functional Status 6MWD (m) 9.52 (-15.53/34.58) 4.25 (-9.78/18.28) 0.704 - Quality of Life PedsQL 3.0 (score: 0-100) 2.0 (-1.0/6.0) 0.5 (0.0/4.0) 0.470 - *Student’s t test, ES: Effect size (Hedge’s g), CI: Confidence Interval, FVC: Forced vital capacity, FEV 1 : forced expiratory volume in the first second, l: litres, %: percent, PI max : maximal inspiratory pressure, PE max : maximal expiratory pressure, cmH 2 O: centimeters water, VO 2peak : peak oxygen consumption, m: meters, ml: milliliters, min: minute, kg: kilograms, MET: Metabolic Equivalent, HR peak : peak heart rate, HRR: heart rate reserve, 6MWD: six-minute walk distance, PedsQL 3.0: The Pediatric Quality of Life Inventory 3.0 Arthritis Module Acknowledgements: NIL. Disclosure of Interests None Declared.