Relationship Between the Triglyceride-glucose Index and Incident Ischemic Heart Disease Risk: A Prospective Study Using National Health Insurance Data

Background: Ischemic heart disease (IHD) without diabetes is considered an important challenge to human health and is associated with a poor prognosis as well as a lack of health awareness. Until now, the association between early insulin resistance and IHD among nondiabetic adults has been poorly understood. We prospectively investigated the relationship between the triglyceride-glucose (TyG) index, a surrogate marker of early insulin resistance, and incident IHD risk in a large cohort of nondiabetic adults using National Health Insurance data. Methods: : We assessed 16,455 participants (8,426 men and 8,029 women) without diabetes using data from a health risk assessment study (HERAS) and Korea Health Insurance Review & Assessment (HIRA) data. The participants were divided into four groups according to TyG index quartiles, calculated as ln [fasting triglycerides (mg/dL) × fasting plasma glucose (mg/dL)/2]. We prospectively assessed hazard ratios (HRs) with 95% confidence intervals (CIs) for IHD, using multivariate Cox proportional-hazards regression models, over a 50-month period that followed the baseline survey. Results: : During the follow-up period, 322 (2.0%) participants developed IHD. HRs of IHD for TyG index quartiles 1–4 were 1.00, 1.63 (95% CI, 1.06–2.49), 1.88 (95% CI, 1.23–2.87), and 2.35 (95% CI, 1.53–3.61), respectively, after adjusting for age, sex, body mass index, smoking status, alcohol intake, physical activity, high sensitivity C-reactive protein, and mean arterial blood pressure. Conclusion: A higher TyG index precedes and significantly predicts future IHD among nondiabetic Koreans. Accordingly, a high TyG index may be a useful additional measure in assessing cardiovascular risks for apparently healthy adults in clinical practice.