The relationship between neutrophil percentage to albumin ratio and proteinuria in different stages of chronic kidney disease: a prospective study

Aims: This study aimed to evaluate the associations of high-sensitivity C-reactive protein (hs-CRP) and the neutrophil percentage-to-albumin ratio (NPAR) with renal dysfunction indicators, including proteinuria, serum creatinine levels, and glomerular filtration rate (GFR), in patients at different stages of chronic kidney disease (CKD), and to explore their potential relevance as markers of disease severity. Methods: A total of 86 CKD patients were included and categorized into four stages (II, IIIA, IIIB, and IV) in this cross-sectional study with prospectively collected data. Demographic, clinical, and laboratory variables—including hs-CRP, NPAR, urine protein-creatinine ratio (UPCR), serum creatinine, and estimated GFR (eGFR)—were recorded. Spearman’s rank correlation was applied to evaluate the associations of hs-CRP and NPAR with other clinical indicators. Additionally, receiver operating characteristic (ROC) curve analysis was performed to evaluate the discriminative ability of hs-CRP and NPAR for identifying advanced CKD stages. Results: Significant variations in hs-CRP, NPAR, serum creatinine, and eGFR levels were identified across different stages of CKD. Both hs-CRP and NPAR showed strong positive correlations with UPCR and serum creatinine (p<0.01), and negative correlations with eGFR (p<0.01). ROC analysis revealed that hs-CRP and NPAR demonstrated high discriminative accuracy for CKD stages IIIA, IIIB, and IV, with sensitivity values of 91.2%, 89.7%, and 91.2% for hs-CRP, and 88.7%, 91.1%, and 91.4% for NPAR, respectively. These findings indicate that both biomarkers are associated with disease severity in CKD. Conclusion: Both hs-CRP and NPAR are associated with disease severity in CKD, demonstrating high sensitivity and discriminative performance in identifying advanced CKD stages and reflecting proteinuria burden. These biomarkers may offer a useful adjunct for monitoring CKD patients and guiding therapeutic interventions.