# Association of the triglyceride-glucose index with carotid intima-media thickness in type 2 diabetes: effect modification by age and albuminuria—a retrospective cross-sectional study

## TL;DR

The study shows that the TyG index, a marker of insulin resistance, is more strongly linked to artery thickening in younger or early-stage kidney-damaged type 2 diabetes patients.

## Contribution

This study reveals that the TyG-IMT relationship is modified by albuminuria and age, highlighting population-specific risks.

## Key findings

- The TyG index showed a stronger positive correlation with IMT in patients with ACR >30 mg/g compared to those with ACR ≤30 mg/g.
- The association between TyG and IMT was significant in patients under 50 years old but diminished in older age groups.
- A graded increase in the TyG-IMT correlation was observed across higher ACR quartiles.

## Abstract

The Triglyceride-Glucose (TyG) index, a surrogate marker of insulin resistance, is associated with increased cardiovascular risk. However, its relationship with subclinical atherosclerosis in diabetic patients with early-stage kidney injury, characterized by an elevated urinary albumin-to-creatinine ratio (ACR), remains unclear. This study examined the association between carotid intima-media thickness (IMT) and the TyG index, specifically investigating how this association is modified by albuminuria status.

This cross-sectional study included 507 patients with type 2 diabetes and preserved kidney function who had ACR values of 0–300 mg/g. Participants were stratified into quartiles based on ACR levels. IMT was measured using high-resolution B-mode ultrasonography. The relationship between the TyG index and IMT was evaluated using partial correlation and multivariate linear regression analyses, with emphasis on assessing this relationship across ACR-based strata.

A weak positive correlation was observed between the TyG index and IMT overall (r = 0.12, P = 0.035), with a significant interaction effect of ACR (p = 0.008). Stratification by ACR showed that for patients with ACR ≤ 30 mg/g, each unit increase in the TyG index was associated with a 0.038 mm increase in IMT (95% CI: 0.015–0.061, p = 0.002), while for those with ACR > 30 mg/g, the increase was 0.071 mm per unit (95% CI: 0.036–0.106, p < 0.001). Furthermore, a graded pattern was observed across ACR quartiles, with the positive correlation between TyG and IMT showing graded strengthening (β values increased from 0.022 to 0.078, p for trend <0.001;). Finally, the TyG–IMT correlation exhibited age specificity, being significant in patients under 50 years (<40 years: β = 0.085, p = 0.002; 40–49 years: β = 0.051, p = 0.015) and diminishing in older age groups.

The association between the TyG index and IMT exhibits stage-specific and population-heterogeneous patterns. A significant, ACR-dependent positive correlation was observed, with the association being pronounced in patients with elevated ACR (>30 mg/g) and in those younger than 50 years. These findings suggest that the pro-atherogenic effect of insulin resistance is more pronounced in diabetic patients with early albuminuria or in younger individuals, underscoring the need for enhanced vascular management to reduce insulin resistance in these high-risk populations.