Work

Hepatorenal index and an exploratory combined model for identifying moderate-to-severe histologic steatosis in patients with liver injury of undetermined etiology

Year: 2026

Type: article

Abstract: Background Liver biopsy is the reference standard for grading hepatic steatosis, but its invasiveness limits routine use. We evaluated the hepatorenal index (HRI), derived from routine two-dimensional grayscale ultrasound images, and an exploratory combined model incorporating HRI with clinical parameters for identifying moderate-to-severe histologic steatosis (S ≥ 2) in patients with liver injury of undetermined etiology. Methods This retrospective single-center cohort included 80 biopsy-referred patients who had undergone same-day grayscale ultrasound, liver stiffness measurement, and liver biopsy. HRI was calculated offline. The exploratory combined model used Firth bias-reduced logistic regression followed by intercept correction, with 1,000-resample bootstrap internal validation. Results The S0, S1, S2, and S3 groups comprised 46, 17, 12, and 5 patients, respectively. Median HRI differed among the S0–S1, S2, and S3 groups (1.02, 1.25, and 1.59; P < 0.001). Body mass index (BMI), prognostic nutritional index (PNI), and HRI were positively associated with S ≥ 2 steatosis, whereas the aspartate aminotransferase-to-platelet ratio index (APRI) was inversely associated. HRI yielded an apparent area under the receiver operating characteristic curve (AUROC) of 0.866 (95% CI, 0.782–0.950). At the data-derived cutoff of >1.05, HRI identified all 17 S ≥ 2 cases, with an apparent sensitivity of 100.00% (95% CI, 80.49%–100.00%) and an apparent specificity of 60.32%. The exploratory combined model yielded an apparent AUROC of 0.942 and a bootstrap optimism-corrected AUROC of 0.927. Conclusion HRI showed promising apparent discrimination and potential rule-out value requiring independent validation. The combined model retained high discrimination after bootstrap correction and may provide a low-cost adjunct where dedicated fat quantification is unavailable, but remains hypothesis-generating pending external validation.

Source: Frontiers in Medicine

DOI: 10.3389/fmed.2026.1995617