Effect of the Respiratory Muscle Training on Lung Function and Respiratory Muscle Strength in Patients with Moderate Myasthenia Gravis: A Meta-Analysis and Systematic Review

Abstract

Background: Respiratory muscle impairment is common in patients with moderate Myasthenia Gravis. Whether respiratory muscle training (RMT) improve lung function tests and/or respiratory muscle strength is still debatable. Methods: A systematic review and a meta-analysis including the relevant randomized controlled trials (RCTs) and prospective studies published from June 1996 and June 2016 and assessing the effect of the (RMT) on the respiratory muscle tests and the respiratory muscle strength. Results: One RCT and 2 prospective cohort studies were included. Respiratory muscle training was found to improve the Maximal voluntary ventilation (MD=-10.3 L/min; CI95% [-17.95, -2.31]; p=0.01; I2=0%; n=24). However, it improved neither FEV1 (MD=-0.10 L; CI95% [-0.28, 0.08]; p=0.27; I2=0%; n=24) nor the Vital Capacity (MD=-0.06; CI95% [-0.24, 0.13]; p=0.57; I2=0%; n=24). Respiratory muscle training did not significantly improve the Maximal inspiratory pressure (PImax) (MD=-15.35; CI95% [-38.5, 7.8]; I2=97%; n=34). However, it significantly improved the maximal expiratory pressure (PEmax) (MD=- 14.7; CI95% [-18.3, -11.12]; pE‚0.001; I2=51%; n=24). Conclusion: The respiratory muscle training significantly improves the maximal voluntary ventilation and the maximal expiratory pressure. Further studies with larger sample size are required to confirm these findings.