UCSF

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.