Phisical performance and quality of life in dialysis patients: Effects of an exercise program prescribed at hospital and carried out at home

Introduction and Aims: Physical training has positive psychophysical effect in dialysis patients. Exercise programs should be effective, sustainable for patients in terms of intensity-duration-mode of execution, bearable for health services in terms of costs. This preliminary study evaluates the effects on performance and Quality of Life (QOL) of a 6 month-walking program prescribed at hospital and carried out at precise intensity at home. Methods: Thirty-one dialysis patients (19 males,age 65±11) after written informed consent were included into 2 groups: prescribed exercise (E),n=17 and control (C),n=14. Physical performance was assessed by the 6 minute walking distance (6MWD) and the Maximal Speed in an incremental treadmill test (MWTS). The MOS SF-36 questionnaire was used to evaluate the perceived health-related QOL. Postdialysis fatigue was determined by a scale measuring the intensity (1=least,5=worst) and by the number of hours of rest necessary to overcome the fatigue symptoms. Medical therapy, dialysis prescription and haemoglobin levels were maintained constant during the study period. All parameters were reassessed after 180 days. Two daily indoor/outdoor walking sessions (10 minutes each, at a speed 50% below MWTS) on the non-dialysis day were prescribed to the E group. The training speed, slower than the usual pace, was facilitated at home by a digital metronome. The program included a daily record of exercise data and symptoms and a monthly MWTS re-evaluation to adjust the training speed. Results: Eleven patients (E=4,C=7) interrupted the study (death-acute illness n=7, transplantation n=1, others n=3). Twenty patients (E=13,C=7) completed the 6-month program. Despite a different training load performed in relation to different comorbidities, E group patients reported absence of limiting symptoms and/or tiredness during all sessions. MTWS and 6MWD significantly increased in the E group: from 3.4±1.1 to 4.0 ±1.0 Km/h (p=0.0004) and from 308±105 to 351±118m (p=0.0007), respectively. The percentage variation of measured 6MWD from the predicted distance for healthy adults rose from 56 to 64%. No relationship was found between performance variations and total amount of exercise. No variation of performance was detected in the C group (6MWD: from 277±72 to 271±76m; 6MWD-predicted distance from 60 to 59%). Improvements in QOL were observed only in the E group, for the scale scores Bodily Pain, Physical Role, Mental Health (p<0.05), Physical Activity, Emotional Role, Social Activity, Vitality (ns). 6MWD and Mental Health variations were directly correlated (r=0.567,p<0.05). The postdialysis fatigue score and the time of recovery, unmodified in C group, were reduced in the E group (p=0.025). Conclusions: Low-cost exercise programs carefully prescribed at hospital and performed at home on the non-dialysis day, improve performance capacity and QOL of dialysis patients with comorbidities.