Association between triglyceride glucose-body mass index and the staging of non-alcoholic steatohepatitis and fibrosis in patients with non-alcoholic fatty liver disease

Abstract

Objective: The objective of this study was to thoroughly investigate the clinical value of triglyceride glucose-body mass index (TyG-BMI) in patients diagnosed with non-alcoholic fatty liver disease (NAFLD). Specifically, we aimed to determine its association with non-alcoholic steatohepatitis (NASH) and the progression of liver fibrosis.

Methods: The study included 393 patients diagnosed with NAFLD after liver biopsy. The patients were divided into two distinct cohorts: a training cohort (N = 320) and a validation cohort (N = 73). The training cohort was further divided into four groups based on TyG-BMI quartiles. The clinical characteristics of the patients in each group were compared in detail, and the association between TyG-BMI and NASH, NAFLD Activity Score (NAS) ≥ 4, at-risk NASH, significant fibrosis, advanced fibrosis, and cirrhosis was analyzed using multiple models. Additionally, we generated receiver operating characteristic (ROC) curves to evaluate the predictive ability of TyG-BMI for NASH and fibrosis staging in patients with NAFLD.

Results: Patients with higher TyG-BMI values had a significantly higher prevalence of NASH, NAS ≥ 4, at-risk NASH, significant fibrosis, advanced fibrosis, and cirrhosis (all p < .05). TyG-BMI was an independent predictor of these diseases in both unadjusted and adjusted models (all p < .05). ROC curve analysis further revealed the excellent performance of TyG-BMI in predicting NASH, NAS ≥ 4, at-risk NASH, significant fibrosis, advanced fibrosis, and cirrhosis. The validation cohort yielded analogous results. Furthermore, we constructed three multivariate models of TyG-BMI in conjunction with elastography metrics, which demonstrated elevated diagnostic AUC values of 0.782, 0.792, 0.794, 0.785, 0.834, and 0.845, respectively.

Conclusion: This study confirms a significant association between insulin resistance and NAFLD, including at-risk NASH and fibrosis staging, as assessed using the TyG-BMI index. TyG-BMI and its associated multivariate models can be valuable noninvasive indicators for NAFLD diagnosis, risk stratification, and disease course monitoring.

Keywords: Triglyceride glucose-body mass index; liver fibrosis; non-alcoholic fatty liver disease; non-alcoholic steatohepatitis; receiver operating characteristic curve.

Figure 1.

Study flowchart.

Figure 2.

Receiver operating characteristics (ROC) curves of TyG-BMI for predicting NASH (A), NAS ≥ 4 (B), at-risk NASH (C), significant fibrosis (D), advanced fibrosis (E), and cirrhosis (F) in patients with NAFLD in the training cohort.

Figure 3.

Sensitivity and specificity of TyG-BMI for predicting NASH (A), NAS ≥ 4 (B), at-risk NASH (C), significant fibrosis (D), advanced fibrosis (E), and cirrhosis (F) in patients with NAFLD. Individual plots were derived from all individual score cutoffs covering the range where sensitivity was 100% to where specificity was 100%, followed by smoothening of the graph to cover the dynamic range of scores for their intended uses.

Figure 4.

Receiver operating characteristics (ROC) curves of TyG-BMI for predicting NASH (A), NAS ≥ 4 (B), at-risk NASH (C), significant fibrosis (D), advanced fibrosis (E), and cirrhosis (F) in patients with NAFLD in the validation cohort.