Association Between Triglyceride-Glucose Index and Malignant Risk in Thyroid Nodules: A Cross-Sectional Analysis

The aim of this study is to investigate the association between the Triglyceride-Glucose (TyG) index and papillary thyroid carcinoma (PTC) risk, with a particular focus on metabolic, thyroid function, and immunological mechanisms.

A cross-sectional study involving 1,833 participants, including 823 individuals with benign thyroid nodules and 1,010 individuals with PTC, was conducted. The TyG index was calculated using the formula ln[fasting triglycerides (mg/dL) × fasting glucose (mg/dL)/2]. Multivariate logistic regression analyses were performed to evaluate the association between the TyG index and PTC risk, with adjustments made for potential confounders.

The mean age of participants in the PTC group was 47.36 ± 12.12 years and the BTN group was 44.28 ± 10.95 years. In the unadjusted model, the TyG index demonstrated a positive correlation with PTC risk (OR = 1.67, 95% CI: 1.33-2.09, p < 0.0001); however, this association was no longer significant following adjustment (Adjusted OR = 0.94, 95% CI: 0.12-7.03, p = 0.9495), TYG is not a risk factor for benign and malignant thyroid nodules. Stratified analysis revealed that moderate TyG levels were linked to an increased PTC risk among middle-aged participants (OR = 1.45, 95% CI: 1.14-1.86, p = 0.0027). Elevated FT3 levels markedly increased PTC risk (OR = 9.13, 95% CI: 4.92-16.97, p < 0.0001), while reduced FT4 and TSH levels were inversely associated with PTC risk. Thyroid autoantibodies demonstrated complex associations. Proposed mechanisms indicate that insulin resistance may contribute to PTC development through inflammatory pathways and cellular proliferation.

The TyG index alone does not serve as an independent risk factor for PTC; however, the interaction between metabolic dysfunction, thyroid function, and immune markers contributes to thyroid carcinogenesis, providing valuable insights for future research and personalized screening strategies.