A Walking Intervention to Increase Weekly Steps in Dialysis Patients: A Pilot Randomized Controlled Trial

Abstract

Rationale & objective: Patients receiving dialysis report very low physical activity. We implemented a pilot trial to assess the feasibility of a pedometer-based intervention to gather preliminary evidence about its impact on physical activity, symptoms, and surrogates of cardiovascular risk.

Study design: Pilot randomized controlled trial.

Setting & participants: 60 dialysis patients from San Francisco dialysis clinics.

Intervention: Participants were randomly assigned 1:1 to receiving pedometers with weekly step goals or usual care for 3 months.

Outcomes: The primary outcome was step counts, measured using pedometers. Secondary outcomes included physical performance using the Short Physical Performance Battery, the Physical Function and Vitality scales of the 36-Item Short Form Health Survey, the Dialysis Symptoms Index, and the Center for Epidemiologic Studies-Depression Scale, with endothelial function as a secondary and heart rate variability as an exploratory surrogate measure of cardiovascular risk. Targeted enrollment was 50% and targeted completion was 85%.

Results: 49% of approached patients were enrolled, and 92% completed the study. After 3 months, patients randomly assigned to the intervention (n=30) increased their average daily steps by 2,256 (95% CI, 978-3,537) more than the 30 controls (P<0.001). Heart rate variability (standard deviation of N-N intervals) increased by 14.94 (95% CI, 0.31-33.56) millisecondsin the intervention group as compared with controls (P = 0.05). There were no statistically significant differences across intervention groups in symptoms, physical performance, or endothelial function. Participants in the intervention group reverted to baseline steps during the postintervention follow-up.

Limitations: The Northern California study setting may limit generalizability. Walking does not capture the full spectrum of physical activity.

Conclusions: A short-term pedometer-based intervention led to increased step counts in dialysis patients, but the increase was not sustained. Pedometer-based interventions are feasible for dialysis patients, but future studies are needed to address whether more prolonged interventions can improve physical function or symptoms.

Funding: Supported by grants from the American Kidney Fund, National Institutes of Health-National Institute of Diabetes and Digestive and Kidney Diseases, and International Society of Nephrology.

Trial registration: Registered at ClinicalTrials.gov with study identifier NCT02623348.

Keywords: Physical activity; activity patterns; dialysis; end-stage renal disease (ESRD); endothelial function; exercise; heart rate variability (HRV); pedometer; physical function; physical performance; quality of life (QoL); randomized controlled trial (RCT); sedentary lifestyle; step counts; symptoms; walking.

Published by Elsevier Inc.

Figures

Figure 1.. Recruitment and Randomization

All patients available for follow-up were included in the primary analysis.

Figure 2.. Average Daily Step Count at Baseline, 3 months, and 6 months