Nonlinear Relationship Between the C-Reactive Protein to Albumin Ratio and Chronic Kidney Disease: A Cross-Sectional Analysis Using the NHANES Database

ObjectiveThe C-reactive protein to albumin ratio (CAR) has gained attention as an inflammatory biomarker with potential relevance in various diseases. However, its relationship with chronic kidney disease (CKD) remains inadequately understood. This study aims to investigate the association between CAR and CKD prevalence in a diverse, multi-ethnic U.S. cohort. MethodsThis cross-sectional analysis utilized data from the 1999-2010 National Health and Nutrition Examination Survey (NHANES). Multivariable regression and subgroup analyses were conducted to control for confounding factors and examine the link between CAR and CKD. A restrictive cubic spline model was employed to explore potential nonlinear associations. ResultsAmong 30,049 participants aged 18 years or older, 5,423 (18.05%) had CKD. Compared to the lowest quartile (Q1) of log-transformed CAR, CKD risk was higher in the second (Q2), third (Q3), and fourth (Q4) quartiles, with odds ratios of 1.28, 1.29, and 1.63, respectively. A dose-response relationship was observed, indicating that higher CAR levels were significantly associated with increased CKD risk. ConclusionElevated CAR is independently associated with a higher prevalence of CKD, suggesting its potential utility as a biomarker for CKD risk assessment in diverse populations. Further studies are needed to confirm these findings and explore underlying mechanisms.