Association of walking with survival and RRT among patients with CKD stages 3-5

Abstract

Background and objectives: Patients with CKD can benefit from an increase in physical activity. Walking is one of the most common exercises in patients with CKD; however, the association of walking with outcomes in patients with CKD is not clear. This study investigated the association of walking with overall mortality and RRT in patients with CKD stages 3-5.

Design, setting, participants, & measurements: All patients with CKD stages 3-5 in the CKD program of China Medical University Hospital from June 2003 to May 2013 were enrolled. The risks of overall mortality and RRT were analyzed using competing-risks regressions.

Results: A total of 6363 patients (average age, 70 years) during a median of 1.3 (range=0.6-2.5) years of follow-up were analyzed. There were 1341 (21.1%) patients who reported walking as their most common form of exercise. The incidence density rate of overall mortality was 2.7 per 100 person-years for walking patients and 5.4 for nonwalking ones. The incidence density rate of RRT was 22 per 100 person-years for walking patients and 32.9 for nonwalking ones. Walking, independent of patients' age, renal function, and comorbidity, was linked to lower overall mortality and lower RRT risk in the multivariate competing-risks regression. The adjusted subdistribution hazard ratio (SHR) of walking was 0.67 (95% confidence interval [95% CI], 0.53 to 0.84; P<0.001) for overall mortality and 0.79 (95% CI, 0.73 to 0.85; P<0.001) for the risk of RRT. The SHRs of overall mortality were 0.83, 0.72, 0.42, and 0.41 for patients walking 1-2, 3-4, 5-6, and ≥7 times per week, and the SHRs of RRT were 0.81, 0.73, 0.57, and 0.56, respectively.

Conclusions: Walking is the most popular form of exercise in patients with CKD and is associated with lower risks of overall mortality and RRT. The benefit of walking is independent of patients' age, renal function, and comorbidity.

Keywords: chronic kidney disease; dialysis; mortality; walking.

Figure 1.

Cumulative incidence of (A) overall mortality and (B) RRT was lower in walking patients than in no walking patients in adjusted competing-risks regression. Multivariate competing-risks regression adjusted for patients’ age, eGFR, body mass index, coronary artery disease, diabetes mellitus, cerebrovascular accident, and cancer.