The CRP-to-Uric Acid Index (CURI): A Novel Inflammatory Metabolic Index to Enhance Noninvasive Screening for MASLD and Liver Fibrosis

BackgroundMetabolic dysfunction-associated steatotic liver disease (MASLD) and significant liver fibrosis (SLF) require noninvasive screening. This study evaluates the C-reactive protein-to-uric acid index (CURI), combining inflammation and metabolic dysfunction, as a biomarker for early detection of MASLD and SLF. MethodsUsing NHANES 2017-2020 data (n=6,687), participants were divided into training and validation cohorts. CURI was calculated as high-sensitivity C-reactive protein (hs-CRP; mg/L) x [uric acid (mg/dL)]3. Associations with MASLD and SLF were analyzed via logistic regression, restricted cubic splines, and mediation analysis considering insulin resistance and adipose indices. Diagnostic performance was evaluated using the area under the curve (AUC), decision curve analysis (DCA), comparing CURI with established indices: fatty liver index (FLI), hepatic steatosis index (HSI), and fibrosis-4 (FIB-4). ResultsMASLD and SLF prevalence were 49.6% and 10.7%, respectively. CURI was independently associated with MASLD and SLF. Nonlinear relationships were observed. Combining CURI with FLI, HSI, or FIB-4 improved diagnostic performance compared to using them alone (AUC for MASLD: 0.852 with FLI, 0.819 with HSI, 0.690 with FIB-4; AUC for SLF: 0.811 with FLI, 0.750 with HSI, 0.699 with FIB-4, p<0.001). DCA showed net benefit for MASLD. Mediation analysis show 98.1% (MASLD) and 84.8% (SLF) of effects. ConclusionCURI is a promising, cost-effective biomarker for MASLD/SLF risk stratification. HighlightsO_ST_ABSWHAT IS KNOWNC_ST_ABSO_LIMASLD and SLF require noninvasive screening. C_LIO_LIExisting methods like liver biopsy are invasive. C_LIO_LIIndices like FLI, HSI, and FIB-4 are commonly used for screening. C_LI WHAT IS NEW HEREO_LICURI is a novel biomarker combining inflammation and metabolic dysfunction for screening. C_LIO_LICURI is independently associated with MASLD and SLF. C_LIO_LICURI enhances prediction when combined with FLI or HSI. C_LIO_LIInsulin resistance mediates most of CURI effect on MASLD and SLF. C_LIO_LICURI is a cost-effective tool for risk stratification in resource-limited settings. C_LI