Respiratory muscle strength: Effects on functional capacity, quality of life and fatigue in women with multiple sclerosis

The aim of our study was to investigate the effect of respiratory muscle strength on functional capacity, fatigue and quality of life (QoL) in patients with multiple sclerosis (pwMS). Thirty-two fully ambulatory female pwMS were included in the study. The maximum expiratory pressure (MEP) and inspiratory pressure (MIP) were recorded for respiratory muscles strength. Functional capacity was assessed with the 6-Minute Walk Test (6MWT), fatigue with Fatigue Impact Scale and Fatigue Severity Scale, and QoL with the MSQoL-54. The partial correlation was made for removing the effect of age and examining the relationship between parameters. There were significant correlations between MIP and functional capacity, change in health, social function, sexual function and satisfaction sub-parameters of MSQoL-54 (rho:0.579, -0.490, -0.545, -0.594, -0.585 respectively). MEP had also significant correlations with functional capacity, change in health, social function, sexual function and satisfaction (rho:0.708, -0.490, -0.556, -0.608, -0.572 respectively). Conversely, no relation was found between respiratory muscle strength and fatigue. Respiratory muscle strength is an important factor that effects functional capacity and different QoL dimension such as sexual functions. It should be evaluated the earliest period in pwMS. However, fatigue is a multidimensional and complex phenomenon that cannot be simply associated with respiratory muscles strength.