Association between triglyceride-glucose index and arteriosclerosis in patients with type 2 diabetes and its mediating effect

To explore the relationship between the triglyceride-glucose (TyG) index and arteriosclerosis in patients with type 2 diabetes mellitus (T2DM), evaluate the direct and indirect effects of the TyG index on arteriosclerosis, and identify potential mediating variables. A total of 410 patients with type 2 diabetes mellitus (T2DM) hospitalized at the Third Affiliated Hospital of Soochow University from January 2021 to December 2023 were included. The patients were divided into an arteriosclerosis group (n = 298) and a non-arteriosclerosis group (n = 112) based on brachial-ankle pulse wave velocity (ba-PWV) values. Clinical data and glucose-lipid metabolism indicators were collected. The association between the TyG index and arteriosclerosis was analyzed using multivariable logistic regression. Curve fitting was performed using a generalized additive model, and stratified analysis was conducted to evaluate the interaction between subgroups. Finally, a mediation effect model was used to analyze the direct and indirect effects of the TyG index on arteriosclerosis. After adjusting for confounding factors, an elevated TyG index significantly increased the risk of arteriosclerosis (OR = 2.748, 95% CI: 1.442–5.237, P = 0.002). The risk was substantially higher in the group with high TyG levels (OR = 3.420, 95% CI: 1.458–8.023, P = 0.005), and the trend test showed that the risk increased with higher TyG index levels (P for trend = 0.005). A smooth curve fitting showed a positive linear relationship between the TyG index and arteriosclerosis (P = 0.002). Stratified analysis revealed no significant interaction between the TyG index and arteriosclerosis across different blood pressure parameters and ankle-brachial index (ABI) subgroups (all P > 0.05). Mediation effect analysis indicated that the mediating effect of ABI in this relationship accounted for -10.9% (P = 0.030). The TyG index is significantly associated with the risk of arteriosclerosis in patients with type 2 diabetes, with ABI partially mediating this relationship.