Association of UACR and UPCR with kidney failure: analysis of observational data in children with chronic kidney disease

Sheila M., Hofstetter J., KARABAY BAYAZIT A., DÜZOVA A., Obrycki L., Doyon A., ...Daha Fazla

Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association, cilt.41, sa.2, 2026 (SCI-Expanded, Scopus)

Özet

BACKGROUND: Urinary albumin-to-creatinine ratio (UACR) and protein-to-creatinine ratio (UPCR) are established markers for risk stratification in pediatric chronic kidney disease (CKD), yet their relative strength of association with CKD progression remains unclear. We compared a head-to-head evaluation of UACR and UPCR associations with estimated glomerular filtration rate (eGFR) decline and kidney survival in a large pediatric CKD cohort. METHODS: We analyzed 596 children aged 6-17 years with CKD stages 3-4 from the 4C cohort. Baseline UACR and UPCR were log-transformed and z-standardized. CKD progression was evaluated by annual eGFR slope and a composite kidney outcome (50% eGFR loss, eGFR <10 mL/min/1.73 m² or kidney replacement therapy). Associations per 1-SD increase were estimated using adjusted linear mixed-effect and Cox models. Differences in effect sizes were assessed using bootstrap-based bias-corrected and accelerated 95% confidence intervals (CI). RESULTS: Mean (SD) age was 12.4 (3.3) years; 70% had congenital anomalies of the kidneys and urinary tract (CAKUT). Median (interquartile range) eGFR was 28 (14) mL/min/1.73 m². Over a median follow-up of 2.5 (3.8) years, 334 events occurred. A 1-SD increase in log-UACR and log-UPCR was associated a 2.17-fold (95% CI 1.84 to 2.55) and 1.70-fold (95% CI 1.52 to 1.90) higher risk of the composite outcome, respectively; UACR showed a 28% stronger association (HRUACR/HRUPCR = 1.28; 95% CI 1.12 to 1.53). No relative difference was found in overall eGFR slope change (slope ∆UACR - slope ∆UPCR = -0.05; 95% CI -0.50 to 0.24), but UACR showed stronger associations in children with advanced CKD and severe proteinuria. CONCLUSION: Both UACR and UPCR were independently associated with CKD progression in this pediatirc cohort. In direct comparison, UACR demonstrated stronger associations with adverse kidney outcomes, suggesting a comparatively greater prognostic signal and supporting current guideline emphasis on albuminuria for risk stratification and intervention outcome monitoring.