Physical Activity and Clinical Outcomes in Patients on Hemodialysis

Patients receiving maintenance hemodialysis have different patterns of physical activity on hemodialysis days and non-hemodialysis days. However, it is unknown whether there is an association between those differences and clinical outcomes. Shohei Yamamoto, PT, MSc, and colleagues conducted an analysis to assess the association of physical activity levels on dialysis and non-dialysis days with cardiovascular hospitalizations and mortality.

Results were reported in the Journal of Renal Nutrition [2021;31(4):380-388].The outcomes of interest were all-cause mortality and a composite of cardiovascular hospitalizations and mortality.

Patients undergoing hemodialysis at outpatient centers from 2002 to 2019 were retrospectively enrolled. Accelerometry was used to record the number of steps over 3 hemodialysis days and 4 non-hemodialysis days. Patients were divided into two groups, each according to the median number of steps performed on hemodialysis days (2371 steps/day) and non-hemodialysis days (3752 steps/day). The cohort was then categorized into four groups according to each median value: (1) more active on hemodialysis/more active on non-hemodialysis days (MM); (2) more active on hemodialysis/less active on non-hemodialysis days (ML); (3) less active on hemodialysis/more active on non-hemodialysis days (LM); and (4) less active on hemodialysis/less active on non-hemodialysis days (LL).

The analysis included data on 512 patients; median follow-up was 3.4 years. There were associations between higher physical activity on hemodialysis and non-hemodialysis days and lower risk of mortality (hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.54-0.65 and HR, 0.84; 95% CI, 0.80-0.88, respectively). Mortality risks were greater in the ML group (HR, 1.20; 95% CI, 1.13-1.28), the LM group (HR, 1.82; 95% CI, 1.53-2.17), and the LL group (HR, 1.83; 95% CI, 1.65-2.02) compared with the MM group. Associations between physical activity with multiple cardiovascular hospitalizations and mortality were similar to those between physical activity and mortality.

In conclusion, the researchers said, “Higher physical activity on hemodialysis and non-hemodialysis days was associated with lower risks of cardiovascular hospitalizations and mortality. However, higher physical activity levels on either hemodialysis or non-hemodialysis days alone did not improve clinical outcomes.”