Exercise in Patients on Dialysis: A Multicenter, Randomized Clinical Trial

Abstract

Previous studies have suggested the benefits of physical exercise for patients on dialysis. We conducted the Exercise Introduction to Enhance Performance in Dialysis trial, a 6-month randomized, multicenter trial to test whether a simple, personalized walking exercise program at home, managed by dialysis staff, improves functional status in adult patients on dialysis. The main study outcomes included change in physical performance at 6 months, assessed by the 6-minute walking test and the five times sit-to-stand test, and in quality of life, assessed by the Kidney Disease Quality of Life Short Form (KDQOL-SF) questionnaire. We randomized 296 patients to normal physical activity (control; n=145) or walking exercise (n=151); 227 patients (exercise n=104; control n=123) repeated the 6-month evaluations. The distance covered during the 6-minute walking test improved in the exercise group (mean distance±SD: baseline, 328±96 m; 6 months, 367±113 m) but not in the control group (baseline, 321±107 m; 6 months, 324±116 m; P<0.001 between groups). Similarly, the five times sit-to-stand test time improved in the exercise group (mean time±SD: baseline, 20.5±6.0 seconds; 6 months, 18.2±5.7 seconds) but not in the control group (baseline, 20.9±5.8 seconds; 6 months, 20.2±6.4 seconds; P=0.001 between groups). The cognitive function score (P=0.04) and quality of social interaction score (P=0.01) in the kidney disease component of the KDQOL-SF improved significantly in the exercise arm compared with the control arm. Hence, a simple, personalized, home-based, low-intensity exercise program managed by dialysis staff may improve physical performance and quality of life in patients on dialysis.

Keywords: CKD; dialysis; exercise; physical functioning; rehabilitation; six minute walking test.

Copyright © 2017 by the American Society of Nephrology.

Figures

Figure 1.

CONSORT diagram of the flow of patients across the various phases of the trial. All baseline measurements (including 6MWT and 5STS) were done after randomization. Baseline demographic data, main cardiovascular comorbidities, and results of the 6MWT and 5STS in patients who completed the 6-month training program and those who dropped out in the two study arms are detailed in Supplemental Table 4.

Figure 2.

Effect of the study interventions on walking capacity (6MWT) and lower limb strength (5STS) in the two arms of the study. The figures overlying the columns are SD of the corresponding mean values. The P value compares changes (6 months versus baseline) between the two groups (exercise versus control).

Figure 3.

Dose–response relationship between achieved physical performance by the 6MWT and 5STS across the control arm and the low adherence and high adherence to the exercise program (active arm). The bars are SD of the mean. Low and high adherence were defined as performance of Supplemental Material.

Figure 4.

Kaplan–Meier survival curves of hospitalizations in the active and control arms of the trial. The left panel shows analysis of all randomized patients. The right panel shows analysis of patients who completed the 6-month trial.