Change in Physical Activity and Function in Patients with Baseline Advanced Nondialysis Chronic Kidney Disease.

BACKGROUND AND OBJECTIVES: Although progressive declines in physical activity and function are common in individuals with worsening chronic kidney disease (CKD), little is known about the impact of dialysis initiation. We assessed for any association of progression to dialysis in people with advanced CKD with temporal rates of change in physical activity and function. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: Canadian Frailty Observation and Interventions Trial (CanFIT) participants with eGFR <30mL/min/1.73m2 were included. Outcomes included change in physical activity level measured using Physical Activity Scale for the Elderly (PASE) and physical function measured using chair stand test, 4-meter gait speed, and grip strength. Generalized linear regression models were conducted to determine whether dialysis initiation was associated with greater decline in physical activity or function. RESULTS: Of 386 individuals, 162 progressed to dialysis. Both assessments were completed by 98% of individuals for PASE, 86% for chair stand test, 84% for gait speed, and 91% for grip strength. Median inter-assessment follow-up was 427 days (IQR 357-578) for the stable advanced CKD group and 606 days (IQR 428-1000) for the progressed to dialysis group. Self-reported physical activity and gait speed significantly declined in both groups. Mean (SD) chair stand time increased from 20.8 (17.1) to 24.0 (21.0) seconds among patients with stable advanced CKD and from 18.5 (15.4) to 27.4 (22.2) seconds among those who progressed to dialysis (adjusted difference in change 5.2seconds, 95% CI 0.8-9.7seconds). Compared to individuals with stable advanced CKD, the progressed to dialysis group experienced greater rise in chair stand time in unadjusted (difference in change 6.05seconds, 95% CI 2.36-9.74, p=0.001) and adjusted (beta estimate 5.23seconds, 95% CI 0.75-9.71, p=0.02) models. CONCLUSIONS: Patients with advanced CKD experience progressive declines in physical activity and function. Transition to dialysis is associated with accelerated decline in physical function measured by chair stand test.