Home-Based Exercise Improves Muscle Oxidative Capacity in Kidney Disease

Muscle impairment in chronic kidney disease (CKD) contributes to decreased physical performance, frailty, and increased mortality. This proof-of-concept randomized controlled study evaluated the efficacy of a 12-week home-based, video-supervised exercise program on muscle endurance in moderate-to-severe nondialysis CKD.

Thirty-two sedentary adults with CKD (estimated glomerular filtration rate [eGFR] < 60 ml/min per 1.73 m²) were randomized (3:1) to a home exercise group (EX, n = 23) or usual care group (UC, n = 9). The primary outcome was in vivo muscle mitochondrial bioenergetics (rate of phosphocreatine recovery, k_PCr) measured using phosphorus-31 magnetic resonance spectroscopy. Secondary outcomes included 6-minute walk test (6MWT) distance (6MWD), total work, peak oxygen consumption (VO₂peak), and work efficiency obtained from cardiopulmonary exercise testing (CPET). Other outcomes were body composition and plasma cytokines. Within- and between-group differences were analyzed using linear mixed models (LMMs).

Mean (SD) ages were 62.6 (10.8) years in EX and 67.2 (8.2) in UC. Mean eGFRs were 35.0 (12.6) and 32.3 (12.0) ml/min per 1.73 m², respectively. No serious adverse events occurred; 90.5% of EX completed ≥ 75% of sessions. Compared with UC, EX significantly increased k_PCr (0.20/min, 95% confidence interval [CI]: 0.05-0.35, P = 0.01), total work (5.03 kJ, 95% CI: 1.25-8.80, P = 0.007), and 6MWD (39.1 m, 95% CI: 7.1-71.1, P = 0.014) while preserving fat-free mass (2.3 kg, 95% CI: 0.49-4.1, P = 0.024) and marginally decreasing fat mass (-2.22 kg, 95% CI: -4.7 to 0.27, P = 0.1) . Interleukin (IL)-8 concentration differed between groups (effect size: -1.16, 95% CI: -2.4 to -0.04, P = 0.016). Work efficiency, VO₂peak, and other cytokines showed no significant differences between groups.

Home-based, video-supervised exercise is feasible, improves muscle oxidative capacity and endurance, offering a strategy to mitigate functional decline in moderate-to-severe nondialysis CKD.