Change in Physical Activity and Function in Patients with Baseline Advanced Nondialysis CKD

Although progressive decline in physical activity and function are common in individuals with worsening CKD, little is known about the effect of dialysis initiation on physical activity. We assessed for any association of progression to dialysis in people with advanced CKD with temporal rates of change in physical activity and function.

Canadian Frailty Observation and Interventions Trial (CanFIT) participants with an eGFR of <30 ml/min per 1.73 m² were included. Outcomes included change in physical activity level, measured using the Physical Activity Scale for the Elderly, and physical function, measured using the chair stand, 4-m gait speed, and grip strength tests. Generalized linear regression models were conducted to determine whether dialysis initiation was associated with greater decline in physical activity or function.

Of 386 individuals, 162 progressed to dialysis. Both assessments were completed by 98% of individuals for the Physical Activity Scale for the Elderly, 86% for the chair stand test, 84% for the gait speed test, and 91% for the grip strength test. Median (interquartile range) interassessment follow-up was 427 (357-578) days for the "stable advanced CKD" group and 606 (428-1000) days 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, 5.2 seconds; 95% confidence interval, 0.8 to 9.7 seconds; P=0.02).

Patients with advanced CKD experience progressive declines in physical activity and function. Transition to dialysis is associated with accelerated decline in physical function, as measured by the chair stand test.