Self-Reported Physical Activity and Survival in Adults Treated With Hemodialysis: A DIET-HD Cohort Study

INTRODUCTION: Regular physical activity is associated with longevity in adults receiving hemodialysis, but it is uncertain whether this association varies by causal pathways (cardiovascular and noncardiovascular). METHODS: DIET-HD was a prospective, multinational study of adults undergoing hemodialysis across Europe and Argentina. We classified participants as physically inactive, occasionally active (irregularly to once a week), or frequently active (twice a week or more), using a self-reported questionnaire. Potential confounders were balanced across exposure groups using propensity scores. Weighted Cox proportional hazards models with double robust estimators evaluated the association between physical activity and all-cause, cardiovascular, and noncardiovascular mortality. RESULTS: Of 8043 participants in DIET-HD, 6147 (76%) had information on physical activity. A total of 2940 (48%) were physically inactive, 1981 (32%) occasionally active, and 1226 (20%) frequently active. In a median follow-up of 3.8 years (19,677 person-years), 2337 (38%) deaths occurred, including 1050 (45%) from cardiovascular causes. After propensity score weighting, occasional physical activity was associated with lower all-cause (adjusted hazard ratio [aHR] = 0.80, 95% CI = 0.72–0.89), cardiovascular (aHR = 0.82, 95% CI = 0.70–0.96), and noncardiovascular (aHR = 0.81, 95% CI = 0.69–0.94) mortality compared with inactivity. Frequent physical activity was associated with lower all-cause (aHR = 0.82, 95% CI = 0.71–0.95) and cardiovascular (aHR = 0.77, 95% CI = 0.62–0.94) mortality, but not noncardiovascular mortality (aHR = 0.88, 95% CI = 0.72–1.08). A dose-dependent association of physical activity with cardiovascular death was observed (P trend = 0.01). CONCLUSION: Compared with self-reported physical inactivity, occasional and frequent physical activities were associated, dose dependently, with lower cardiovascular mortality in adults receiving hemodialysis.