Effects of intradialytic exercise training on health-related quality of life indices in haemodialysis patients

Objective: To assess the effects of intradialytic exercise training on health-related quality of life indices in haemodialysis patients. Subjects/patients: Thirty-five patients on haemodialysis, with a mean (SD) age of 48.8 (13.9) years, volunteered to participate in the study. They were randomized either to rehabilitation group (group A: 19 patients), following a 10-month intradialytic exercise training programme or to control group (group B: 14 patients). After the randomization, two of the patients, one of each group, withdrew from the study for reasons unrelated to exercise training. Method: All patients at the beginning and the end of the study underwent clinical examination, laboratory tests and a treadmill exercise testing with spiroergometric study for the evaluation of their aerobic capacity (Vo(2peak)). A formal psychosocial assessment, which included affective (Beck Depression Inventory), health-related quality of life (Quality of Life Index, Living Questionnaire of Minnesota, Life Satisfaction Index and Short Form-36 questionnaire) and personality (Eysenck Personality Questionnaire) parameters, was evaluated at beginning and end of the study. The dose of erythropoietin was changed as needed, according to the level of the haemoglobin, aiming to keep it at 11 (2) g/dL during the study. Results: Baseline values were similar between the two groups. After training in group A, Vo(2peak) was increased by 21.1% (P < 0.05) and exercise time by 23.6% (P < 0.05). Moreover, group A showed a decrease in self-reported depression (Beck Depression Index) of 39.4% (P < 0.001). In addition, trained patients demonstrated a significant improvement in Quality of Life Index (from 6.5 (1.8) to 9.0 (1.3), P < 0.001) and Life Satisfaction Index (from 44.8 (8.6) to 53.0 (5.6), P < 0.001), and an increase in the Physical Component Scale of the SF-36 (from 40.5 (5.6) to 44.5 (5.5), P < 0.05), while the Mental Component Scale remained unchanged. Multiple regression analysis indicated that the improvement in quality of life depended on the participation in exercise programmes, the effects of training and the reduction in the level of depression. No changes were observed in Eysenck Personality Questionnaire by the end of the study, while all the above parameters remained almost unchanged in the controls. Conclusion: The results demonstrated that intradialytic exercise training improves both physical functioning and psychological status in haemodialysis patients, leading to an improvement of patients' quality of life.