Impairments of Muscle Strength, Exercise Capacity, and Quality of Life in Patients With Systemic Sclerosis: A Cross-Sectional Study

Abstract

Background Functional capacity and muscle weakness are affected in patients with systemic sclerosis (SSc). However, upper extremity functional exercise capacity has not been sufficiently studied in patients with SScObjective The primary objective was to compare upper extremity functional exercise capacity; secondary objectives were to compare functional exercise capacity, pulmonary function, respiratory muscle strength, balance, peripheral muscle strength, dyspnea, fatigue, quality of life (QoL), and physical activity in patients with SSc and healthy controls.Methods Twenty-five patients and 25 healthy controls were included in this cross-sectional study. The upper extremity functional exercise capacity [6-min pegboard and ring test (6-PBRT)], functional exercise capacity [6-Minute Walking Test (6-MWT)], pulmonary function, respiratory muscle strength, balance, peripheral muscle strength, fatigue, dyspnea, QoL, and physical activity were assessed. Between-group comparisons used Student's t-test, the Mann-Whitney U test, or the Chi-square test as appropriate. Effect sizes (Cohen's d) were calculated for key outcomes.Results Compared to controls, patients with SSc had significantly lower 6-PBRT scores (Cohen's d = 3.29), 6-MWT distances (Cohen's d = 1.87), pulmonary function, respiratory and peripheral muscle strength, balance, QoL, and physical activity levels, with higher dyspnea and fatigue levels (p < 0.05).Conclusions Patients exhibited impaired upper extremity functional exercise capacity, functional exercise capacity, pulmonary function, respiratory muscle strength, balance, peripheral muscle strength, QoL, and physical activity, as well as increased levels of dyspnea and fatigue compared to healthy controls. Therefore, after a comprehensive assessment including upper extremity functional exercise capacity, patients with SSc should be initiated into cardiopulmonary rehabilitation programs.