Association of Physical Activity and Poor Health Outcomes in Patients With Advanced CKD.

Rationale & Objective: Chronic kidney disease (CKD) is associated with declining physical function and activity. In the general population, lower physical activity is associated with poorer quality of life and greater all-cause mortality. The aim of this study was to assess if lower physical activity levels are associated with adverse health outcomes in patients with advanced CKD.

Study Design: A multicenter prospective cohort study.

Setting & Participants: 579 adult patients with CKD glomerular filtration rate categories 4 and 5 (G4-G5) treated at 4 Canadian multidisciplinary kidney health clinics between 2012 and 2018.

Exposure: Patient-reported measures of physical activity using the Physical Activity Scale for the Elderly (PASE) questionnaire and subsequently stratified PASE scores into tertiles.

Outcome: All-cause mortality, progression to kidney failure, and future falls.

Analytical Approach: Outcomes were analyzed using time-dependent proportional hazards models and logistic regression models.

Results: In 1,193 days of follow-up observation, 118 patients died, 204 progressed to dialysis, and 129 reported a fall. When compared with low physical activity, higher levels of physical activity were associated with a 52% lower all-cause mortality (adjusted HR, 0.48; 95% CI, 0.27-0.85) in models adjusted for age, sex, and comorbidity. No associations were detected between higher levels of physical activity and either slower progression to kidney failure or a lower rate of future falls.

Limitations: Physical activity and falls were self-reported. Our population was of limited racial/ethnic diversity, which may affect generalizability. Findings were observational and do not indicate whether interventions targeting physical activity may affect adverse health outcomes.

Conclusions: Higher levels of physical activity were associated with about 50% lower all-cause mortality in the advanced CKD population. These findings are consistent with a potential benefit from maintained physical activity as patients approach kidney failure.