Beyond Body Mass Index: Body Roundness Index Identifies Individuals at Risk for Metabolic Dysfunction–Associated Alcohol-Related Liver Disease: A Cross-Sectional Study

Background/Objectives: Metabolic dysfunction and alcohol-associated liver disease (MetALD) is characterized by the coexistence of metabolic dysfunction with moderate alcohol consumption. Anthropometric indices have emerged as simple, non-invasive tools for assessing metabolic, cardiovascular, and hepatic steatosis risks; however, their association with MetALD is unclear. We evaluated the association between anthropometric indices and MetALD and assessed their discriminative performance. Methods: We analyzed 2645 NHANES 2017–2020 participants with transient elastography data, including 165 with MetALD. Body roundness index (BRI) was categorized into weighted quartiles. Results: MetALD participants had significantly worse metabolic profiles and higher liver enzymes than controls (all p < 0.001). Severe steatosis increased across BRI quartiles from 1.8% in Q1 to 33.3% in Q4, while fibrosis increased from 0% to 6.7%. Higher BRI quartiles were independently associated with MetALD after adjustment for age, sex, race, BMI, and WC (OR 4, 11.1, and 12.8 for Q2, Q3, and Q4, respectively; all p < 0.012). Non-Hispanic Asian participants had an increased risk of MetALD (OR 3; p = 0.016). Waist circumference (WC) demonstrated the highest discriminative performance for MetALD (area under the curve [AUC] = 0.773), followed by BRI (AUC = 0.743). Gamma-glutamyl transferase (GGT) demonstrated the highest discrimination value (AUC = 0.776) for predicting MetALD, while the combined WC and GGT showed the highest overall performance (AUC of 0.817). Conclusions: Higher BRI is independently associated with MetALD, along with greater steatosis and fibrosis severity. Simple anthropometric measures may aid early identification and risk stratification of MetALD.