Supervised Exercise Intervention and Overall Activity in CKD

Abstract

Introduction: Patients are often instructed to engage in multiple weekly sessions of exercise to increase physical activity. We aimed to determine whether assignment to a supervised exercise regimen increases overall weekly activity in individuals with chronic kidney disease (CKD).

Methods: We performed a secondary analysis of a pilot randomized 2 × 2 factorial design trial examining the effects of diet and exercise (10%-15% reduction in caloric intake, 3 supervised exercise sessions/wk, combined diet restriction/exercise, and control). Activity was measured as counts detected by accelerometer. Counts data were collected on all days for which an accelerometer was worn at baseline, month 2, and month 4 follow-up. The primary outcome was a relative change from baseline in log-transformed counts/min. Generalized estimating equations were used to compare the primary outcome in individuals in the exercise group and the nonexercise group.

Results: We examined 111 individuals randomized to aerobic exercise or usual activity (n = 48 in the exercise group and n = 44 controls). The mean age was 57 years, 42% were female, and 28% were black. Median overall adherence over all time was 73%. Median (25th, 75th percentile) counts/min over nonsupervised exercise days at months 2 and 4 were 237.5 (6.5, 444.4) for controls and 250.9 (7.7, 529.8) for the exercise group (P = 0.74). No difference was observed in the change in counts/min between the exercise and control groups over 3 time points (β [fold change], 0.96, 95% confidence interval [CI], 0.91, 1.02).

Conclusion: Engaging in a supervised exercise program does not increase overall weekly physical activity in individuals with stage 3 to 4 CKD.

Keywords: accelerometer; chronic kidney disease; counts per minute; exercise; physical activity; randomized.

Graphical abstract

Figure 1

Consolidated Standards of Reporting Trials (CONSORT) flow diagram. Participants lost to follow-up were excluded in compliance analyses.

Figure 2

Mean days that accelerometer was worn at baseline, month 2, and month 4 for controls and exercise groups.

Figure 3

Boxplot of counts/min over month 2 and month 4 for controls and exercise groups for (a) nonexercise days and (b) all accelerometer days.

Figure 4

Boxplot of counts/min at baseline, month 2, and month 4 for controls and exercise groups for (a) nonexercise days and (b) all accelerometer days.