Ethnic-specific ZJU index thresholds for hepatic steatosis and fibrosis in Chinese MASLD

Background The Zhejiang University (ZJU) index correlates with metabolic dysfunction-associated steatotic liver disease (MASLD) in Chinese cohorts, but its ethnic-specific thresholds for hepatic steatosis and fibrosis remain undefined. Methods A cross-sectional study of 2,156 Chinese MASLD patients used vibration-controlled transient elastography (VCTE) and restricted cubic spline (RCS) modeling to analyze ZJU index associations with controlled attenuation parameter (CAP) and liver stiffness measurement (LSM). Results The ZJU index independently correlated with both controlled attenuation parameter (CAP, β = 0.96 dB/m) and liver stiffness measurement (LSM, β = 0.042 kPa). Crucially, we identified ethnic-specific thresholds for Chinese populations (CAP: 46.38; LSM: 49.49) that are significantly lower than Western cohorts, characterized by rapid pre-threshold risk escalation and post-threshold plateaus. The strongest correlations appeared in males, the elderly, and non-obese individuals. Sensitivity analyses using multiple imputation showed materially consistent results. In addition, comparative analyses indicated that the ZJU index had generally comparable discriminatory performance compared to conventional indicators, outperforming several metabolic markers for fibrosis-related outcomes, although body mass index (BMI) and waist circumference showed slightly higher area under the curve (AUC) values in some fibrosis models. Conclusion The ZJU index is a cost-effective tool for Chinese MASLD assessment, with ethnic-specific thresholds critical for accurate disease stratification in resource-limited settings.