The predictive value of triglyceride-glucose index for in-hospital and one-year mortality in elderly non-diabetic patients with ST-segment elevation myocardial infarction.

Abstract

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). 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. 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. 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.