Diagnostic Role of Ultrasound Abdominal Fat Index in Detecting Obesity, Hepatic Steatosis, and Metabolic Syndrome Risk

Abstract Background: Intra-abdominal obesity contributes significantly to metabolic dysfunction and hepatic steatosis. Abdominal Fat Index (AFI), obtained from ultrasonographic measurements of preperitoneal and subcutaneous fat, has emerged as a simple, non-invasive marker of metabolic risk. Purpose: To evaluate the diagnostic role of AFI in detecting obesity, fatty liver, and associated metabolic comorbidities. Material and methods: This cross-sectional study included 1634 adults undergoing abdominal ultrasonography. Anthropometric parameters (BMI, waist and hip circumference, waist-to-hip ratio) and metabolic comorbidities were recorded. Preperitoneal and subcutaneous fat thickness were measured to calculate AFI. Fatty liver was graded and statistical analysis were performed. Results: Of 1634 participants, 67.0% were overweight and 33.0% obese. Fatty liver was detected in 83.7% (Grade (1): 45.7%, Grade (2): 32.4%, Grade (3): 5.6%). Hypertension 39.2% and diabetes 24.9% were most common. AFI increased significantly with fatty liver severity and was higher in obese vs overweight patients 1.03 vs 0.98; p < 0.001. AFI correlated positively with BMI, waist circumference, and waist-to-hip ratio. Regression analysis identified waist-to-hip ratio, waist circumference, and BMI as independent predictors of AFI. ROC analysis demonstrated fair discrimination for fatty liver (AUC 0.72, 95% CI 0.687-0.752, p < 0.001, with diagnostic accuracy of 84%. Conclusion: Ultrasound-derived AFI is a reliable, non-invasive marker associated with obesity, fatty liver grading, and metabolic comorbidities, and may serve as a useful screening tool in clinical practice.