Comparative Diagnostic Performance of Non-Invasive Indices for Predicting Ultrasonographic Hepatic Steatosis in Morbidly Obese Patients: A Single-Center Retrospective Study

Objectives: Morbid obesity is strongly associated with non-alcoholic fatty liver disease (NAFLD), and hepatic steatosis is highly prevalent among candidates for bariatric surgery. Given the invasive nature of liver biopsy, there is a growing need for reliable non-invasive methods to assess hepatic steatosis. This study aimed to compare the diagnostic performance of insulin resistance–based indices (Homeostasis Model Assessment of Insulin Resistance [HOMA-IR] and Quantitative Insulin Sensitivity Check Index [QUICKI]) and biochemical scores (Hepatic Steatosis Index [HSI] and NAFLD Liver Fat Score [NAFLD-LFS]) in predicting ultrasonographically detected hepatic steatosis in patients with morbid obesity.
Methods: In this single-center retrospective observational study, 206 patients with morbid obesity who underwent primary laparoscopic sleeve gastrectomy between March 2024 and February 2026 and had available preoperative laboratory and abdominal ultrasonography data were included. Insulin resistance indices (HOMA-IR, QUICKI) and composite scores (HSI and NAFLD-LFS) were calculated. Hepatic steatosis was graded ultrasonographically as grade 1–3 and categorized as mild (grade 1) and moderate-to-severe (grade ≥2) for diagnostic performance analyses. Receiver operating characteristic (ROC) curve analysis was performed to evaluate diagnostic accuracy.
Results: Hepatic steatosis was classified as grade 1 in 28.2%, grade 2 in 59.2%, and grade 3 in 12.6% of patients. Steatosis grade showed positive correlations with HOMA-IR (r=0.244), HSI (r=0.354), NAFLD-LFS (r=0.297), HbA1c (r=0.274), transaminases, and glucose/insulin levels, and a negative correlation with QUICKI. In ROC analysis, HSI demonstrated the highest diagnostic performance (AUC=0.716), followed by HbA1c (AUC=0.656) and NAFLD-LFS (AUC=0.645). In multivariable analysis, age (OR=1.04), BMI (OR=1.23), and NAFLD-LFS (OR=1.42) were identified as independent predictors, while female sex was associated with lower risk (OR=0.34).
Conclusion: In patients with morbid obesity, hepatic steatosis is significantly associated with metabolic parameters and insulin resistance. Among non-invasive indices, HSI demonstrated the highest diagnostic performance. HSI and NAFLD-LFS may serve as practical tools in the preoperative assessment of bariatric surgery candidates.

Keywords: Hepatic steatosis, hepatic steatosis index, morbid obesity, NAFLD liver fat score, non-invasive indices