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 stage 3-5 CKD underwent a randomized controlled trial of a 12-week home-based personalized exercise program consisting of high-intensity interval training, power walking, and strength training versus usual care. Patients had vastus lateralis muscle biopsy before and after intervention to assess muscle changes. Patients in the exercise cohort did not have significant changes to fiber size, fiber type, number of satellite cells. While there were no changes in measures of fibrosis (collagen content or ECM area), fibro-adipogenic 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 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.