Association of Triglyceride-glucose Index with Intra- and Extra-cranial Arterial Stenosis: A Combined Cross-sectional and Longitudinal Analysis

Purpose This study aimed to assess the cross-sectional and longitudinal associations of the triglyceride glucose (TyG) index, a simple surrogate marker of insulin resistance, with intra-cranial and extra-cranial artery stenosis (ICAS and ECAS) in Chinese adults. Methods Participants were recruited from the Asymptomatic Polyvascular Abnormalities Community study, 5381 participants were enrolled in the cross-sectional analysis, then 3447 and 1853 participants in the longitudinal analysis for incident ICAS and ECAS, respectively. The TyG index was calculated as ln [fasting triglyceride (mg/dL) × fasting glucose (mg/dL)/2]. Multivariable logistic analysis was used to calculate odds ratio (OR) and 95% confidence interval (CI). Results The results of the cross-sectional and longitudinal analysis were basically the same, as the fully adjusted OR comparing participants in the highest tertile versus lowest tertile of the TyG index was 1.34 (95% CI, 1.13-1.59) for the prevalence of ECAS and 1.85 (95% CI, 1.26-2.71) for incident ECAS, respectively. The addition of TyG index to a conventional model had an incremental effect on the predictive value for ECAS. However, we did not observe any significant association between the TyG index and ICAS. Conclusions Elevated TyG index was significantly associated with a higher risk of ECAS, but not with ICAS in Chinese adults. This conclusion lends support to the clinical significance of the TyG index for the assessment of artery stenosis, especially for ECAS.