Leisure-Time Physical Activity and Mortality in CKD: A 1999-2012 NHANES Analysis

For patients with CKD, evidence on the optimal dose of physical activity and possible harm with excessive exercise is limited. This study aimed to analyze the dose-response association between leisure-time physical activity (LTPA) and mortality in those with CKD and explore the optimal dose or possible harm associated with increased levels of LTPA.

4,604 participants with CKD from the 1999 to 2012 National Health and Nutrition Examination Surveys with linked mortality data obtained through 2015 were classified into 6 groups: 0, 1-149, 150-299, 300-599, 600-899, and ≥900 min/week based on the total duration of the self-reported LTPA. Multivariable-adjusted Cox proportional hazards models were used to examine dose-response associations between LTPA and mortality.

During the median follow-up of 114 months, 1,449 (31%) all-cause deaths were recorded. Compared to the inactive group (0 min/week), we observed a 22% lower risk of all-cause mortality (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.63-0.97) among participants who performed 1-149 min per week for LTPA. The corresponding HRs and 95% CIs for all-cause mortality for 150-299 and 300-599 min/week of LTPA were 0.79 (0.64-0.97) and 0.74 (0.56-0.98). The benefit appeared to reach a threshold of a 43% (HR, 0.57; 95% CI, 0.36-0.91) lower risk of all-cause mortality among individuals performing 600-899 min/week for LTPA. Importantly, for ≥900 min/week of LTPA, the continued benefits were observed (HR, 0.62; 95% CI, 0.44-0.87).

LTPA was associated with lower mortality in those with CKD. The optimal dose was observed at the LTPA level of approximately 600-899 min/week, and there were still benefits rather than the excess risk with LTPA levels as high as ≥900 min/week. Therefore, clinicians should encourage inactive CKD patients to perform LTPA and do not need to discourage CKD patients who already adhere to long-term physical activity.