Purpose: High doses of glucocorticoids induce skeletal muscle weakness. The aim of this study was to evaluate the effects of exercise therapy on skeletal muscle strength, mass, and exercise capacity in patients with connective tissue disease treated with high doses of glucocorticoids.
Methods: This prospective, observational, single-center, cohort study included 35 patients aged ≥ 15 years diagnosed with connective tissue disease who received high-dose glucocorticoids and physical training. Exercise therapy, including moderate aerobic and strength training, was performed five times a week. Knee extension strength, skeletal muscle mass, anaerobic threshold, and peak oxygen consumption were measured at the beginning of exercise therapy and at discharge.
Results: After 6 weeks of aerobic and strength exercises, skeletal muscle mass significantly decreased by 5.5%, right knee extension decreased by 11.6%, and left knee extension decreased by 9.7%. The anaerobic threshold and peak oxygen consumption significantly increased by 13.0% and 9.0%, respectively. The increase in glucocorticoid dose was inversely correlated with changes in knee extension strength.
Conclusion: In patients with connective tissue disease being treated with high-dose glucocorticoids, exercise therapy might attenuate the decrease in skeletal muscle mass and strength and increase the anaerobic threshold and peak oxygen consumption, thus moderating the side effects of high-dose glucocorticoid treatment. Trial registration The trial is registered with UMIN (University Hospital Medical Information Network), ID number UMIN000038836.
Keywords: Connective tissue disease; Exercise therapy; Exercise tolerance; Glucocorticoids; Muscle strength.