Abstract
BACKGROUND: Triglyceride-glucose (TyG) index, a reliable marker of insulin resistance, was associated with cardiovascular morbidity and mortality. This study aimed to evaluate the predictive value of TyG index for mortality in elderly non-diabetic patients with ST-segment elevation myocardial infarction (STEMI). METHODS: In total, 430 non-diabetic patients aged over 65 years with STEMI were consecutively included. The TyG index was calculated by using the following formula: TyG index = ln (fasting triglyceride × fasting glucose/2). The 5-item modified frailty index score was utilized to determine comorbidities. Patients were divided into three groups based on TyG index tertiles. RESULTS: Patients included into high TyG index tertile were male and had higher body mass index, glucose, triglyceride, low-density lipoprotein cholesterol, 5-item modified frailty index and GRACE risk score; and had low systolic blood pressure, estimated glomerular filtration rate and left ventricular ejection fraction. A one-unit increase in TyG index was associated with 3.03 extra cases per 1000 person-day for in-hospital mortality and 0.29 extra cases per 1000 person-day for long-term mortality. There was a non-linear relationship between TyG index and the risk of mortality with an increased risk above 8.5 for TyG index. Kaplan-Meier survival curves revealed that patients in high TyG index tertile had higher in-hospital and long-term mortality rates than those in low TyG index tertile. CONCLUSIONS: This was the first study to demonstrate that the TyG index could predict in-hospital and long-term mortality in elderly non-diabetic STEMI patients.