Association between the triglyceride-glucose index and arterial stiffness in adolescents: the Wakayama study

Insulin resistance plays an important role in early vascular dysfunction during adolescence. The triglyceride-glucose (TyG) index is a simple surrogate marker of insulin resistance. This study aimed to examine the association between the TyG index and arterial stiffness in adolescents. This cross-sectional study included 617 adolescents aged 15-18 years in a school-based setting. Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV) using an automated oscillometric device with appropriately sized cuffs. Blood samples were collected after an overnight fast to calculate the TyG index and the homeostasis model assessment of insulin resistance (HOMA-IR). When participants were categorized into tertiles of the TyG index, baPWV increased significantly across tertiles. This association was observed in both obese and non-obese participants. In multivariable linear regression models adjusting for age, sex, systolic blood pressure, BMI z-score, heart rate, HDL cholesterol, HbA1c, and serum uric acid, the TyG index remained independently associated with baPWV; however, this association was attenuated after further adjustment for HOMA-IR. Receiver operating characteristic curve analysis showed that the area under the curve for the TyG index was comparable to that for HOMA-IR in identifying elevated baPWV. These results suggest that the TyG index was significantly associated with arterial stiffness in adolescents, regardless of obesity status. Although its predictive performance was similar to that of HOMA-IR, the TyG index may serve as a practical marker of early vascular alterations in this population.