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

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.

Respiratory muscle impairment in dialysis patients: can minimal dose of exercise limit the damage? A Preliminary study in a sample of patients enrolled in the EXCITE trial.

AIM: Skeletal muscle atrophy and dysfunction with associated weakness may involve the respiratory muscles of dialysis patients. We evaluated the effect of moderate-intensity exercise on lung function and respiratory muscle strength. METHODS: Fifty-nine patients (25 F, aged 65 ± 13 years) from two centers participating in the multicenter randomized clinical trial EXerCise Introduction To Enhance Performance in Dialysis (EXCITE) were studied. Subjects were randomized into a prescribed exercise group (E), wherein subjects performed two 10-min walking sessions every second day at an intensity below the self-selected speed, or a control group (C) with usual care. Physical performance was assessed by the 6-min walk test (6MWT). Patient lung function and respiratory muscle strength were evaluated by spirometry and maximal inspiratory pressure (MIP), respectively. RESULTS: Forty-two patients (14 F) completed the study. At baseline, the groups did not differ in any parameters. In total, 7 patients (4 in E; 3 in C) showed an obstructive pattern. The pulmonary function parameters were significantly correlated with 6MWT but not with any biochemical measurements. Group E safely performed the exercise program. At follow-up, the spirometry parameters did not change in either group. A deterioration of MIP (-7 %; p = 0.008) was observed in group C, but not in group E (+3.3 %, p = ns). In E, an increase of 6MWT was also found (+12 vs. 0 % in C; p = 0.038). CONCLUSION: In dialysis patients, a minimal dose of structured exercise improved physical capacity and maintained a stable respiratory muscle function, in contrast to the control group where it worsened.