The triglyceride glucose-waist circumference is the best indicator for screening non-alcoholic fatty liver disease in middle-aged and elderly people.

Background: this investigation aimed to assess the correlation between the triglyceride glucose (TyG) index and its related indicators, as well as the ratio of triglyceride to high-density lipoprotein cholesterol (TG/HDL-c), with hepatic steatosis and liver fibrosis among middle-aged and elderly participants.

Methods: based on data from the 2017-2020 National Health and Nutrition Examination Survey, the study included adults of ages 40 years and older in the United States. To explore the correlation between TyG and its related indicators, as well as TG/HDL-c with hepatic steatosis and liver fibrosis, multiple regression models were employed. In addition, the receiver operating characteristic curves were used to further explore the diagnostic efficacy of these indicators in non-alcoholic fatty liver disease (NAFLD) and liver fibrosis.

Results: following the adjustment for various possible covariates, TyG, triglyceride glucose-body mass index (TyG-BMI), triglyceride glucose-waist circumference (TyG-WC), as well as TG/HDL-c were positively correlated with controlled attenuation parameter and NAFLD, with corresponding β coefficients of 17.90, 0.19, 0.20, and 1.57, alongside odds ratios of 2.10, 1.01, 1.01, and 1.15, respectively (all p < 0.05). The β coefficient for the association between TyG and liver stiffness measurement was -0.43 (p = 0.023). Notably, the area under the curve (AUC) of TyG-WC was the highest of all parameters, showing strong diagnostic potential for identifying NAFLD (AUC = 0.79) and liver fibrosis (AUC = 0.75).

Conclusions: this study reveals a significant positive correlation between TyG-WC and the prevalence of NAFLD in middle-aged and elderly people in the United States. These findings highlight that lowering TyG-WC levels may help reduce the incidence of NAFLD in middle-aged and older Americans.