Beneficial Effect of Intradialytic Electrical Muscle Stimulation in Hemodialysis Patients: A Randomized Controlled Trial

Many hemodialysis (HD) patients cannot perform self-administered exercise training for their muscle wasting, weakness, and sarcopenia. Electrical muscle stimulation (EMS) has the advantages of easy application, and minimal risks for these patients. This study aimed to evaluate the effects of intradialytic EMS. This was a prospective, open-label, randomized controlled trial. Twenty-nine HD patients were randomly assigned to either the EMS group or the control (no training) group, and 13 patients in each group were eventually analyzed. The EMS group received intradialytic EMS over an 8-week period. Measurement of isometric knee extensor strength using a handheld dynamometer, evaluation of the quadriceps cross-sectional area (CSA) using magnetic resonance imaging (MRI), the Timed Up & Go Test (TUG) for physical function assessment, the Japanese version of the Short Form-8 Health Survey (SF-8), and blood tests were performed before and after the intervention period. The primary and secondary outcomes were improvement of quadriceps muscle strength and size, respectively. The EMS group demonstrated significant improvement compared with the control group in terms of knee extensor strength (right: 22.3 +/- 12.8 vs. -10.8 +/- 22.3 N, P < 0.001; left: 26.1 +/- 29.7 vs. -8.3 +/- 18.7 N, P < 0.001), quadriceps CSA at three positions, 25, 50, and 75% of the segment length from the greater trochanter to the inferior border of the lateral epicondyle of the femur (25% right: EMS group 1.7 +/- 2.0 vs. Control group -0.4 +/- 1.8 cm(2), P = 0.05; 25% left: EMS group 1.3 +/- 1.1 vs. Control group -0.6 +/- 1.8 cm(2), P = 0.01; 50% right: EMS group 2.0 +/- 2.2 vs. Control group -0.7 +/- 1.9 cm(2), P = 0.004; 50% left: EMS group 2.7 +/- 2.1 vs. Control group -0.7 +/- 1.6 cm(2), P = 0.001; 75% right: EMS group 1.8 +/- 2.2 vs. Control group -0.7 +/- 1.5 cm(2), P = 0.003; 75% left: EMS group 2.1 +/- 1.9 vs. Control group -0.4 +/- 1.5 cm(2), P = 0.003); and TUG time (-0.8 +/- 0.6 vs. 0.2 +/- 0.5 s, P < 0.001). The EMS group showed improvement after intervention in all components of SF-8, but these were not statistically significant. EMS could be an effective exercise training tool for HD patients with either muscle wasting, weakness, or sarcopenia. Key Words: Electrical muscle stimulation-Hemodialysis-Muscle size-Muscle strength-Physical function-Quality of life.