Skeletal muscle adaptation to home-based exercise in chronic kidney disease

Chronic kidney disease (CKD) is commonly associated with decreased physical activity and skeletal muscle dysfunction. It has previously been shown that skeletal muscle fibrosis, impaired regeneration, and decreased vascularization occur in CKD. Independently, exercise can lead to increased muscle fiber size, satellite cells, capillary density, collagen synthesis, and extracellular matrix (ECM) remodeling. To determine the impact of exercise within a CKD population on muscle tissue properties, muscle tissue was examined before and after an exercise program. Twenty-five patients (19 exercisers and 6 usual care) with stages 3-5 CKD underwent a randomized controlled trial of a 12-wk home-based, personalized exercise program consisting of high-intensity interval training, power walking, and strength training versus usual care. Patients had a vastus lateralis muscle biopsy before and after interventions to assess muscle changes. Patients in the exercise cohort did not have significant changes in fiber size, fiber type, or number of satellite cells. Although there were no changes in measures of fibrosis (collagen content or ECM area), fibroadipogenic progenitors decreased with exercise, suggesting that there may be reduced accumulation of fibrosis in the future. There were parallel increases in muscle capillarization, increased in vivo muscle oxidative capacity, and a trending increase in walking distance, showing patients responded to exercise. This highlights that muscle in patients with CKD responded to an endurance-focused, home-based exercise program.NEW & NOTEWORTHY This study investigates the impact of a home-based, video-monitored 12-wk exercise program, consisting of both endurance and resistance exercise, on skeletal muscle structural remodeling in persons with chronic kidney disease. We found this program increased capillaries and decreased fibroadipogenic progenitors after exercise.