Association Between Triglyceride-Glucose Index and Pathological Invasiveness of Lung Adenocarcinoma in Patients With Solitary Ground-Glass Nodules: A Cross-Sectional Study

Background The triglyceride-glucose (TyG) index, a surrogate marker for insulin resistance, has recently been implicated in the development of multiple cancer types. However, its relationship with the pathological invasiveness of lung adenocarcinoma, particularly in patients with pure ground-glass nodules (pGGNs), remains unclear. Methods This retrospective single-center analysis included 278 patients presenting with solitary pGGNs (≤ 3 cm) detected during routine chest CT screenings, who later received surgical resection and histological confirmation of lung adenocarcinoma. Patients were classified into invasive lung adenocarcinoma (ILA) and non-invasive groups [adenocarcinoma in situ (AIS) or minimally invasive adenocarcinoma (MIA)]. The TyG index was calculated using preoperative fasting triglyceride and glucose levels. To evaluate the relationship between TyG and ILA, multivariable logistic regression analyses were performed with adjustment for relevant clinical and imaging-related covariates. Additional subgroup analyses were carried out to assess potential interactions. Results A Higher TyG index was significantly associated with an increased likelihood of ILA. In the fully adjusted model, each 1-unit increase in the TyG index was associated with a 2.61-fold higher odds of ILA (95% CI: 1.32–5.13, P = 0.006). When stratified by tertiles, patients in the highest TyG group had significantly higher odds of ILA than those in the lowest group (OR = 2.69, 95% CI: 1.05–6.87). Subgroup analyses showed consistently positive associations across sex, age, obesity, and other strata, with suggestive effect modifications by sex (P for interaction = 0.057) and T2DM (P for interaction = 0.051). Conclusions A higher TyG index was independently linked to increased pathological invasiveness among patients with solitary pGGNs. These findings suggest a potential role for TyG as a preoperative metabolic biomarker in the risk stratification of lung adenocarcinoma.