Association between physical activity and mortality in end-stage kidney disease: a systematic review of observational studies

Background: End-stage Kidney Disease patients have a high mortality and hospitalization risk. The association of these outcomes with physical activity is described in the general population and in other chronic diseases. However, few studies examining this association have been completed in end-stage Kidney Disease patients, raising the need to systematically review the evidence on the association of physical activity with mortality and hospitalization in this population. Methods: Electronic databases (EBSCO, Scopus and Web of Science) and hand search were performed until March 2020 for observational studies reporting the association of physical activity with mortality or hospitalization in adult end-stage Kidney Disease patients on renal replacement therapy (hemodialysis, peritoneal dialysis and kidney transplant). Methodological quality of the included studies was assessed using the Quality in Prognosis Studies tool. The review protocol was registered in PROSPERO (CRD42020155591). Results: Eleven studies were included: six in hemodialysis, three in kidney transplant, and two in hemodialysis and peritoneal dialysis patients. Physical activity was self-reported, except in one study that used accelerometers. All-cause mortality was addressed in all studies and cardiovascular mortality in three studies. Nine studies reported a significant reduction in all-cause mortality with increased levels of physical activity. Evidence of a dose-response relationship was found. For cardiovascular mortality, a significant reduction was observed in two of the three studies. Only one study investigated the association of physical activity with hospitalization. Conclusions: Higher physical activity was associated with reduced mortality in end-stage Kidney Disease patients. Future studies using objective physical activity measures could strengthen these findings. The association of physical activity with hospitalization should be explored in future investigations.