Abstract
OBJECTIVE: To investigate the relationship between very long chain saturated fatty acids (VLCSFAs) levels in the serum of American adults and chronic kidney disease (CKD), thereby providing new insights for the prevention and treatment of CKD. METHODS: Using data from the 2011-2014 National Health and Nutrition Examination Survey (NHANES), individuals under 20 years of age and those lacking serum creatinine, blood urea nitrogen, urine albumin-to-creatinine ratio (uACR), or other covariate data were excluded. Estimated glomerular filtration rate (eGFR) was calculated using the CKD-EPI (2009) equation. The independent relationship between VLCSFAs and CKD was examined using weighted multivariate logistic regression, the XGBoost machine learning model, and subgroup analyses. Restricted cubic splines (RCS) were used to test for nonlinear associations. RESULTS: A total of 4164 participants were analyzed. Serum VLCSFAs levels differed significantly between the CKD and non-CKD groups (P < 0.05). In fully adjusted models, weighted multivariate logistic regression revealed a decreasing trend in CKD risk with increasing serum VLCSFAs levels, particularly for docosanoic acid, tricosanoic acid, and lignoceric acid, which significantly reduced CKD risk (docosanoic acid: odds ratio [OR] = 0.17, 95% CI: 0.06-0.43, P < 0.001; tricosanoic acid: OR = 0.02, 95% CI: 0.002-0.15, P < 0.001; lignoceric acid: OR = 0.13, 95% CI: 0.04-0.40, P < 0.001). RCS analysis showed no nonlinear association between VLCSFAs and CKD. The XGBoost machine learning model identified triacontanoic acid as the most important factor for CKD risk. Subgroup analysis indicated that docosanoic acid, tricosanoic acid, and lignoceric acid exerted protective effects only in CKD participants with concomitant hypertension, while showing no impact on those with diabetes, coronary heart disease, or stroke. CONCLUSION: Elevated circulating VLCSFAs levels in US adults are associated with reduced CKD risk. Further large-scale prospective studies are needed to validate these findings.