Prediction and Validation of Metabolic Dysfunction-Associated Fatty Liver Disease Using Insulin Resistance-Related Indices in the Japanese Population

Background: Recently, metabolic dysfunction-associated fatty liver disease (MAFLD), which is based on evidence of hepatic steatosis and any of the following three conditions: overweight/obesity, presence of type 2 diabetes mellitus, or evidence of metabolic dysregulation, has been proposed. It is uncertain how indices that predict insulin resistance (IR) are associated with MAFLD. Methods: Among subjects who had undergone health examinations at our hospital, 1,257 (787 men and 474 women) who underwent fatty liver evaluation, were included in this cross-sectional study. The discriminatory ability of each index for MAFLD was tested using a receiver operating characteristic curve analysis. The associations between the homeostasis model assessment-IR (HOMA-IR), triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio, triglyceride-glucose (TyG) index, and MAFLD were investigated using multiple logistic regression analysis. Results: The mean age and body mass index of MAFLD subjects were 58.1 years and 26.0kg/m(2) in men and 63.0 years and 26.1kg/m(2) in women, respectively. The cutoff values of HOMA-IR, TG/HDL-C ratio, and TyG index in men and women were 1.40 (area under the curve [AUC]: 0.81) and 1.90 (AUC: 0.88); 1.56 (AUC: 0.75) and 1.06 (AUC: 0.78); and 8.62 (AUC: 0.75) and 8.45 (AUC: 0.80), respectively. All indices were significantly higher in both men and women with MAFLD. In the multivariate models, the odds of MAFLD were higher among both men and women in the highest tertile than those in the lowest tertile. When subjects were divided by sex, presence of MAFLD, and alanine aminotransferase (ALT) values, all indices were significantly higher in both men and women with high ALT levels who were diagnosed with MAFLD. Conclusion: IR strongly correlated with MAFLD, particularly in subjects with high ALT levels.