Association between triglyceride-glucose index and myocardial injury in patients with heat stroke: an observational, retrospective study

Heat stroke (HS) can lead to myocardial injury (MI), a critical factor affecting patient prognosis. The triglyceride-glucose (TyG) index, a surrogate marker for insulin resistance, has been associated with MI in patients with ischemic stroke and diabetes. However, its relationship with MI in HS patients remains unclear. This study aimed to explore the correlation between the TyG index and MI in HS patients. Clinical data from HS patients admitted to the emergency department of West China Hospital, Sichuan University, between July 1, 2022, and September 30, 2023, were retrospectively analyzed. Patients were divided into MI and non-MI groups based on the presence of MI. MI was defined as cardiac troponin ≥ 1.5 ng/mL. Multivariate logistic regression evaluated the association between the TyG index at admission and MI. A restricted cubic spline (modeled with four knots) was used to assess the dose-response relationship between the TyG index and MI. The study included 169 HS patients (mean age: 55 years; 85 [50.3%] male), of whom 63 (32.7%) developed MI. After adjusting for confounders, multivariate logistic regression revealed a nonlinear association between the TyG index and MI risk. Restricted cubic spline analysis revealed a non-linear relationship between the TyG index and MI risk, with a decreasing trend observed for TyG values ≤ 8.897, followed by a marked increase in risk for values ≥ 8.966. Female patients and those in specific age groups (18-44 and 75-89 years) exhibited higher risk of MI. This study identifies a U-shaped relationship between the TyG index and MI in HS patients, highlighting the TyG index's potential indicator value and underscoring the importance of gender and age in risk assessment.