Effects of electrical stimulation on muscle power and biochemical markers during hemodialysis in elderly patients: a pilot randomized clinical trial

Abstract Background Decreased physical activity in hemodialysis (HD) patients causes various structural, metabolic, and functional abnormalities due to uremic changes in skeletal muscles. Electrical stimulation (ES) of the lower limbs was found to be effective in patients with cardiac insufficiency for exercise tolerance. This study compared the effects of ES and variable load ergometers on the lower limbs in HD patients. Methods We performed a prospective, double-center, open-label, randomized controlled trial. Eligible patients were aged over 65 years, had end-stage renal disease, and underwent maintenance HD. The primary endpoint was muscle power, and the secondary endpoints included changes in dialysis efficiency, serum phosphorus, and inflammatory markers. Thirty HD outpatients were randomly assigned to the following groups: exercise (EX), ES, or control (SED). In EX and ES groups, patients were instructed to exercise twice a week for 12 weeks, depending on their physical capabilities. The safety and efficacy of aerobic training and ES during HD were confirmed when a sudden decrease in blood pressure or any other side effects did not occur. A repeated measures analysis of variance was performed as the principal method to evaluate time (baseline vs. 12 weeks) and group (EX vs. ES vs. SED) comparisons for the experimental outcomes. Results The efficiency of HD significantly increased in the ES and EX groups (p ≤ 0.02). Moreover, the ES group experienced a significant increase in muscle power (p = 0.01) and the weight bearing index (p = 0.04) and a significant decrease in serum phosphorus level (p = 0.04) and tumor necrosis factor-alpha (TNF-α) level (p = 0.04) from baseline to 12 weeks. Furthermore, there was a significant increase in serum TNF-α level (p ≤ 0.03) over time in both the EX and SED groups. Conclusion The safety and efficacy of aerobic training and ES during HD were confirmed when a sudden decrease in blood pressure or any other side effects did not occur. Therefore, ES may improve the patient’s condition, similar to lower limb exercises, and ES should be considered as an option for rehabilitation programs in HD patients. Trial registration UMIN Clinical Trials Registry (UMIN-CTR R 000032202); retrospectively registered on April 11, 2018