Elevated triglyceride-glucose index is a risk factor for cardiovascular events in adults with type 1 diabetes: a cohort study

Background: The triglyceride-glucose (TyG) index is recognized as an indicator of insulin resistance and is linked to cardiovascular disease (CVD) in patients with type 2 diabetes. However, its utility in patients with Type 1 diabetes (T1DM) has not been studied. Methods: In this nationwide cohort study, we enrolled 14,543 patients with T1DM between 2009 and 2015, with a median follow-up duration of 7.52 years. The primary outcome was the incidence of CVD, including myocardial infarction, ischemic stroke, and heart failure. The secondary outcome was the all-cause mortality. The risk of CVD across the TyG index quartiles was compared using the Cox proportional hazards model. Results: The cut-off points for the TyG quartiles were 8.46, 9.03, and 9.60. Patients in the highest TyG quartile exhibited a higher burden of cardiometabolic risk factors, including obesity, hypertension, dyslipidemia, and lower HDL cholesterol levels. Compared to the lowest quartile, the highest TyG quartile group showed a significantly increased risk of CVD (Composite CVD: adjusted hazard ratio [aHR] = 1.80; 95% confidence interval [CI] = 1.62–2.00, myocardial infarction: aHR = 1.70;95% CI = 1.38–2.10, ischemic stroke: aHR = 2.11; 95% CI = 1.78–2.50, heart failure: aHR = 1.65, 95% CI = 1.45–1.88) and all-cause mortality (aHR = 1.60, 95% CI = 1.41–1.81). Conclusions: A higher TyG index was significantly associated with an increased risk of CVD and all-cause mortality in patients with T1DM. Research insights: What is currently known about this topic? The TyG index is associated with insulin resistance and cardiovascular disease in both patients with type 2 diabetes and the general population. What is the key research question? Could the TyG index also be utilized to assess insulin resistance and cardiovascular disease risk in patients with type 1 diabetes? What is new? In patients with type 1 diabetes, those in the higher TyG quartile showed a higher prevalence of metabolic dysfunction such as obesity, hypertension and dyslipidemia. A higher TyG index in patients with type 1 diabetes was associated with an increased risk of all-cause mortality and cardiovascular disease including myocardial infarction, heart failure and stroke. How might this study influence clinical practice? The TyG index, a simple and non-invasive marker composed of triglycerides and fasting glucose, could be used to identify patients with type 1 diabetes who have high insulin resistance and cardiovascular disease risk.