A cross-sectional study of physical activity on non-dialysis and dialysis days: Association with physical functioning

Abstract

Physical inactivity is associated with low levels of physical functioning and adverse outcomes in hemodialysis (HD) patients. However, only a few studies have examined physical activity (PA) on both non-HD and HD days. This study aimed to clarify the association between physical functioning and patients stratified by levels of PA on non-HD and HD days. A total of 269 Japanese HD outpatients (mean age, 64.3 ± 11.6 years; 139 women) were enrolled in this study. Clinical characteristics, physical functioning [handgrip strength (HGS), leg strength (LS), maximum gait speed (MGS), and one-leg standing time (OLS)] and PA were collected and measured. PA was evaluated with an accelerometer as the number of steps per day for a consecutive 7-day period consisting of four non-HD days and three HD days. Patients were categorized into the following three PA groups by using each median value of PA for non-HD and HD days: (1) High/high group (high PA on both non-HD and HD days), (2) High/low group (high PA on either non-HD or HD day), and (3) Low/low group (low PA on both non-HD and HD days). Analysis of covariance was performed to assess associations between groups and physical functioning, with adjustments for age, sex, and body mass index. Low PA was associated with lower physical functioning (all, P trend <0.001). Specifically, both the Low/Low group and High/low group had significantly lower HGS, slower MGS, and poorer OLS compared to the High/High group, even after adjusting for covariates (Fig. 1). PA on both non-HD and HD days was associated with physical functioning, suggesting that PA must be managed in HD patients on both non-HD and HD days.