Predictive Value of Triglyceride Glucose Index for the Development of New-Onset Diabetes Mellitus Following Heart Transplantation

Abstract

<h3>Purpose</h3> Diabetes mellitus (DM) is a major cause of morbidity and mortality following heart transplantation (HT), with 35% being affected within 5 years. Identification of patients at risk for the development of DM could enable prevention and proper intervention. The Triglyceride Glucose (TyG) index is considered a surrogate marker of insulin resistance and is an early indicator for developing type 2 DM in the non-transplant population. We investigated the association between the TyG index and new-onset diabetes after transplantation (NODAT). <h3>Methods</h3> A total of 158 non-DM HT patients were included in the study. The risk of NODAT was assessed according to the 3-month TyG index, calculated as ln[fasting triglycerides (mg/dL) × fasting plasma glucose (mg/dL)/2]. The endpoint was NODAT, defined according to the diagnostic criteria of the American Diabetes Association. <h3>Results</h3> The overall prevalence of NODAT was 20%. The TyG index in the NODAT group was significantly higher than that for the no-NODAT group (9.4 vs 8.7, p <0.001). A TyG index of 8.9 had a sensitivity of 78%, with a specificity of 70% for the prediction of NODAT. Kaplan-Meier survival analysis showed that NODAT rate was significantly higher for patients with a high vs a low TyG index (40 vs 8%, p >0.001, Fig.). Consistently, multivariable analysis, adjusted for age, gender, BMI, immunosuppression, hypertension, and dyslipidemia, showed that a high TyG index was independently associated with a significant 3.3-fold increased risk for NODAT (p = 0.03, Fig.). Patients with a high TyG index had significantly higher rates of peripheral vascular disease (21 vs 8%, p = 0.04) and allograft vasculopathy (48 vs 19%, p <0.001) than patients with a low TyG index. <h3>Conclusion</h3> The TyG index, a simple measure reflecting insulin resistance, might help identify individuals at high risk for developing NODAT. The implications of early interventions, using the TyG index as a marker, on the risk for NODAT and clinical outcomes, should be evaluated.