Association Between Triglyceride–Glucose Body Mass Index and Mortality in Acute Ischemic Stroke Patients With Medium Vessel Occlusion: A Multicenter Retrospective Cohort Study

<title>Abstract</title> <p> Background The triglyceride-glucose body mass index (TyG-BMI), a composite indicator integrating lipid–glucose metabolism and obesity, is associated with insulin resistance and cardiovascular risk; however, its relationship with mortality in acute ischemic stroke (AIS) patients with medium vessel occlusion (MeVO) unclear. Methods This was a multicenter, retrospective cohort study that included patients with MeVO-related AIS from three comprehensive stroke centers between January 2021 and March 2025. Patients were stratified into high and low TyG-BMI groups according to the optimal cutoff value determined by receiver operating characteristic (ROC) analysis. Primary outcomes were 90‑day and 1‑year all‑cause mortality. Survival was compared via Kaplan‑Meier, and TyG‑BMI–mortality associations were assessed using Cox regression and restricted cubic splines,.with interaction and subgroup analyses for robustness. Results Among 187 eligible AIS patients with MeVO (median age 69.0 years; 35.8% male), 18 (9.6%) and 35 (18.7%) died within 90 days and 1 year, respectively. In fully adjusted Cox models, TyG-BMI was independently associated with increased risks of 90-day mortality (HR = 1.027, 95% CI: 1.011–1.043, <italic>P</italic>  = 0.001) and 1-year mortality (HR = 1.024, 95% CI: 1.012–1.037, <italic>P</italic>  &lt; 0.001). RCS analysis indicated a linear positive association between TyG-BMI and both mortality endpoints. Subgroup analyses showed generally consistent associations across strata, with a significant interaction observed for diabetes in relation to 90-day mortality (P for interaction = 0.043). Conclusions The TyG-BMI index is significantly and linearly associated with all-cause mortality in AIS patients with MeVO, suggesting its potential as a risk stratification tool in this population. </p>