The Association between Leisure-Time Physical Activity Intensity and Duration with the Risk of Mortality in Patients with Chronic Kidney Disease with or without Cardiovascular Diseases.

Introduction: For chronic kidney disease (CKD) patients with or without cardiovascular diseases, the associations between leisure-time physical activity intensity (LTPA) and daily exercise time with mortality risk remain unclear.

Method: This study enrolled 3279 CKD patients from National Health and Nutrition Examination Survey (NHANES) 2007-2014 survey. Patients were grouped into different groups according to LTPA intensity (none, moderate, vigorous) and duration (0 min, 0-30 min, 30-60 min, 60 min). We selected the confounders based on their connections with the outcomes of interest or a change in effect estimate of more than 10%. Multivariable-adjusted Cox proportional hazards models were used to examine the associations between LTPA and mortality. The three-knot cubic spline (10, 50, and 90%) was employed to investigate the relationship between the dose of LTPA duration and all-cause death. Patients were divided into different groups according to cardiovascular diseases (CVD).

Results: A total of 564 all-cause death were recorded in this study. Multivariable Cox regression showed that moderate LTPA was associated with a reduced risk of mortality by 38% (hazard ratio (HR): 0.62, 95% confidence interval (CI): 0.44-0.88) in CKD patients, while vigorous LTPA did not have evident survival benefits (HR: 0.91, 95% CI: 0.46-2.64). Subgroups analysis demonstrated that those who engaged in moderate LTPA have a significantly lower risk of mortality (HR: 0.67, 95% CI: 0.47-0.95) in patients without CVD, while patients complicated with CVD did not benefit from the practice (HR: 0.61, 95% CI: 0.37-1.02). Physical exercise for more than 30 minutes was associated with a lower risk of mortality in general CKD patients (30-60 min: HR: 0.23, 95% CI: 0.09-0.58, 60 min: HR: 0.23, 95% CI: 0.08-0.63) and those without CVD (30-60 min/d: HR: 0.32, 95% CI: 0.12-0.83, 60 min/d: HR: 0.20, 95% CI: 0.06-0.71); however, this positive outcome was not seen in patients complicated with CVD (30-60 min/d: HR: 0.67, 95% CI: 0.11-4.04, 60 min/d: HR: 1.14, 95% CI: 0.14-9.11).

Conclusions: Moderate LTPA for more than 30 minutes is associated with a reduced risk of mortality in general CKD patients and those without CVD. However, LTPA did not reduce the risk of mortality in CKD patients complicated with CVD.