Triglyceride-Glucose Indexes Are Predictive of Early and Severe Diabetic Retinal Microvascular Abnormalities: A Prospective Cohort Study.

PURPOSE: To evaluate the associations of the triglyceride-glucose (TyG) index and TyG-derived metrics with diabetic retinopathy (DR) subtypes, retinal lesions, and retinal vascular metrics in adults with type 2 diabetes (T2D).

DESIGN

A population-based, prospective cohort study.

PARTICIPANTS

One thousand nine hundred sixty adults with T2D, followed for a mean of 21.2 months.

METHODS

Outcomes included ETDRS-graded DR subtypes (advanced DR, vision-threatening DR [VTDR], diabetic macular edema [DME]); retinal lesions (hemorrhages/microaneurysms, hard exudates, soft exudates [SE]); and retinal vascular metrics (central retinal artery equivalent, central retinal vein equivalent, arteriole-to-venule ratio). Associations of TyG and TyG-derived indices with these outcomes were assessed using regression models with multivariable adjustments. Restricted cubic spline regression was applied to test for nonlinear associations. Mediation analyses by hemoglobin A1c (HbA1c) were conducted with bootstrap replications. Bonferroni correction was applied to control for type I error.

MAIN OUTCOME MEASURES: Associations of TyG and TyG-derived indices with prevalent and incident DR subtypes, retinal lesions, and retinal vascular metrics.

RESULTS

At baseline, TyG and TyG-WHR (TyG × waist-to-hip ratio) were significantly associated (P ≤ 0.005) with advanced DR (odds ratio [OR] ≥ 2.12), VTDR (OR ≥ 1.77), and DME (OR ≥ 1.79). The TyG and TyG-WHtR (TyG × waist-to-height ratio) were also significantly linked to SE (OR ≥ 1.71, P ≤ 0.005), an early DR vascular abnormality. Longitudinally, TyG-WHtR predicted incident advanced DR (OR range: 1.7-18.8, P = 0.007). Mediation analysis showed HbA1c mediated these associations (P ≤ 0.001), suggesting both glycemic and nonglycemic mechanisms.

CONCLUSIONS

The TyG and its derived indices (TyG-WHR, TyG-WHtR) are associated with the presence and progression of early and severe retinal vascular abnormalities in T2D. These markers may aid in identifying patients at high risk for VTDR.

FINANCIAL DISCLOSURES: The authors have no proprietary or commercial interest in any materials discussed in this article.