Alcoholic Liver Disease/Non-Alcoholic Fatty Liver Disease Index for Classification of Patients with Steatotic Liver Disease.

ABSTRACT

Background: Steatotic liver disease (SLD) encompasses metabolic dysfunction-associated steatotic liver disease (MASLD) and alcohol-associated liver disease (AALD) at extremes as well as an overlap group termed MASLD with increased alcohol intake (Met-ALD). The Alcoholic Liver Disease/Non-Alcoholic Fatty Liver Disease Index (ANI) was proposed to differentiate ALD from non-alcoholic fatty liver disease (NAFLD). We analysed the performance of the ANI in differentiating within the SLD spectrum. Methods: In a cross-sectional study at a tertiary care center, 202 adults (>18 years) who were prospectively diagnosed with SLD defined by magnetic resonance imaging-proton density fat fraction >6.4% were enrolled. Alcohol consumption (AC) was recorded according to thresholds for significant AC 140-350 g/week (or 20-50 g/day) for females and 210-420 g/week (or 30-60 g/day) for males. The ANI was calculated, and area under the receiver operating characteristic curve (AUROC) was generated. Results: Of 202 patients (47 years [interquartile range, IQR, 38 to 55], 23.75% females, 77% obese, 42.1% diabetic, 38.1% hypertensive, 28.7% statin use), 40.5% were ever-alcohol consumers; 120 (59%), 50 (24.7%), and 32 (15.8%) were MASLD (ANI, -3.7 [IQR, -7 to -1.6]; Met-ALD, - 1.45 [IQR, -2.4 to 0.28]; and AALD, 0.71 [IQR, -1.3 to 4.8], respectively; P<0.05 for all). The AUROC of the ANI for MASLD and AALD was 0.79 (0.72 to 0.84; cut-off <-3.5) and 0.80 (0.74 to 0.86; cut-off >-1.49), respectively. The ANI outperformed aspartate transaminase/alanine transaminase (AST/ALT) ratio (AUROC=0.75 [0.69 to 0.81]) and gamma glutamyl transpeptidase (GGT) (AUROC=0.74 [0.67 to 0.80]). Addition of GGT did not improve model performance (AUCdiff=0.004; P=0.33). Conclusion: AC is common in MASLD. The ANI distinguishes MASLD and AALD, with individual cut-offs within the intermediate zone indicating Met-ALD. ANI also outperforms AST/ALT ratio or GGT.