Association of Unhealthy Plant-Based Diet with All-Cause Mortality in Chronic Kidney Disease Without Cardiovascular Diseases: A NHANES-Based Study.

Purpose: A plant-based diet (PBD) has been demonstrated to reduce the risk of chronic kidney disease (CKD) and cardiovascular diseases (CVD). This study aimed to examine the associations of PBD indices with all-cause and CVD mortality in a cohort of community-dwelling adults with predominantly early-stage CKD and no comorbid CVD.

Methods: Adult CKD patients, defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m² and/or urinary albumin-to-creatinine ratio (uACR) >30mg/g, without known CVD, were included from the 1999-2018 National Health and Nutrition Examination Survey. The primary exposures were scores from the healthy PBD index (hPDI), unhealthy PBD index (uPDI), and total PDI. The Cox proportional hazards model was used for survival analysis.

Results: A total of 4098 participants (mean age 55.50 years, mean eGFR 80.62 mL/min/1.73m²) were included. During a median follow-up time of 102 months, 1191 (19.52%) participants died, of which 397 were from CVD mortality. Neither the total PDI nor the hPDI was associated with all-cause or CVD mortality. The hazard ratios and 95% confidence intervals for the association between uPDI and all-cause or CVD mortality were 1.02 (1.01-1.04) and 1.01 (0.98-1.04), respectively. Restricted cubic spline analysis indicated a linearly positive relationship between uPDI and all-cause mortality. Subgroup analysis revealed that the associations between uPDI and all-cause mortality were stronger in women and non-diabetic individuals compared to men and diabetic individuals.

Conclusion: Adherence to unhealthy PBD is associated with increased all-cause mortality in US CKD individuals without CVD, especially women and non-diabetic individuals.