Physical activity levels and mortality in peritoneal dialysis patients.

BACKGROUND: Studies have identified physical inactivity as an important modifiable risk factor for mortality, morbidity, and reduced quality of life in chronic kidney disease patients. Physical activity and patients prognosis has been widely studied in patients with chronic kidney disease or under hemodialysis therapy. However, this association remains unclear in peritoneal dialysis patients. In this study, we investigated the association between the distinct physical activity level or physical activity component and peritoneal dialysis clinical outcomes. METHOD: A total of 117 peritoneal dialysis patients who were admitted to the peritoneal dialysis clinic of Peking University Third Hospital from March to May 2008 were included in this study. Physical activity levels were assessed by the International Physical Activity Questionnaire (IPAQ). The associations between the physical activity behavior or its components and patients’ mortality were analyzed by Cox proportional hazards regression. RESULTS: After median of 4.40 years of follow-up, 74 (63.2%) of the 117 patients died. Median survival time of patients with moderate-intensity physical activity (7.16 years, 95% CI 6.02–8.29, p = 0.011) and vigorous-intensity physical activity (8.55 years, 95% CI 6.97–10.13, p = 0.005) were significantly longer compared to those with low-intensity physical activity (4.88 years, 95% CI 3.63–6.14), respectively. After adjusting for confounding factors, the high level of physical activity (adjusted hazard ratio[aHR] 0.68, 95% CI 0.46–0.98, p = 0.040) was independently associated with reduced mortality. Daily walking time (per 30 min/day) was independently associated with low mortality (aHR 0.86, 95% CI 0.75-1.00, p = 0.045) in peritoneal dialysis patients. CONCLUSION: Although the causality cannot be established, this retrospective cohort study demonstrated that higher physical activity levels and longer daily walking time were associated with favorable clinical outcomes in peritoneal dialysis patients. Given that limited mobility is associated with poorer outcomes, these findings may suggest that the utility of a holistic patient-centered care approach for these patients care planning and prognostic discussions. CLINICAL TRIAL NUMBER: Not applicable.