Associations of combined physical activity and dietary quality with all-cause and cardiovascular disease mortality among US adults with chronic kidney disease

Abstract

Background There is a lack of sufficient information on the impact of physical activity (PA) and dietary quality (DQ) on mortality in patients with chronic kidney disease (CKD), and no study has yet examined the relationship between the combined effects of PA and DQ on the risk of death in patients with CKD in a representative adult population. Methods Adult CKD patients (n = 6,504) from the National Health and Nutrition Examination Survey (NHANES) 1999–2018 were included in the study. Mortality outcomes were assessed by National Death Index records before 2/25/2019. Four lifestyle categories were established: low-PA individuals with unhealthy diets, low-PA individuals with healthy diets, high-PA individuals with unhealthy diets, and high-PA individuals with healthy diets. Cox proportional risk modeling was used to calculate the hazard ratios (HRs) and 95% confidence intervals (CIs) of various lifestyle categories for all-cause and CVD mortality. Results During a median follow-up period of 111 months, 1,971 participants with CKD died from all-cause mortality, and 567 died from CVD among 6,504 respondents. The high-PA CKD population with a healthier diet had a significantly lower risk of all-cause [0.75, 95% CI (0.64–0.87)] and CVD [0.69, 95% CI (0.51–0.93)] mortality than the low-PA, unhealthy diet participants did. The age and race subgroups showed significant interactions, with the older (≥60 years) and non-Hispanic black subgroups experiencing a more favorable risk-lowering effect for all-cause death. Conclusion CKD patients with healthy diets and adequate PA had lower risks of CVD and all-cause mortality than did low-PA individuals with unhealthy diets.