The triglyceride-glucose index as a clinical useful marker for metabolic associated fatty liver disease (MAFLD): a population-based study among Iranian adults

Background and aims There is a bi-directional association between non-alcoholic fatty liver disease (NAFLD) and insulin resistance in type 2 diabetes mellitus (T2DM) and metabolic syndrome. The triglyceride-glucose (TyG) index is a novel surrogate marker of insulin resistance. In this population-based study, we aimed firstly to investigate the association of the TyG-index with metabolic-associated fatty liver disease (MAFLD) risk. Methods This case–control study used the data from the first phase of the Persian Cohort Study in Sabzevar. Of 4,241 participants aged 35 to 70 years, we identified and recruited 968 MAFLD cases and 964 age- and sex-adjusted controls. Demographic, lifestyle, anthropometric, and biochemical information were collected. We calculated TyG and a new index combined of TyG and alanine aminotransferase (TyG-ALT). We used the multivariable unconditional logistic regression model to calculate the odds ratios (ORs) of the TyG and TyG-ALT for having MAFLD. Results Among those in the highest relative to the lowest TyG and TyG-ALT tertiles, the multivariable-adjusted ORs were 12.01 (95% CI [confidence interval] 9.03 – 15.98; P trend < 0.001) and 10.89 (95% CI 7.66 – 15.48; P trend = 0.001), respectively. The area under the curves (AUC) for the TyG-index to predict MAFLD was 8.62, resulting in a cut-off value of 8.62 with a sensitivity of 81.66% and specificity of 75.36%. Conclusions The higher TyG and TyG-ALT scores were significantly positively associated with higher MAFLD risk in the Iranian population.