Inflammatory biomarkers as prognostic tools for diabetic retinopathy progression: a prospective study

AIMS: This study aimed to evaluate the prognostic potential of circulating inflammatory biomarkers, specifically hsCRP, IL-6, TNF-α, and CD163, for predicting diabetic retinopathy (DR) in adults with recently diagnosed type 2 diabetes. METHODS: A prospective cohort of 3,363 individuals from the Danish Centre for Strategic Research in Type 2 Diabetes was followed prospectively (median follow-up of nine years). Baseline concentrations of four biomarkers were measured, and DR outcomes were assessed. Logistic regressions were used to evaluate associations with DR presence at baseline, while Cox regressions were used to analyze the development and progression of DR, adjusting for potential confounders, including HbA1c. RESULTS: No associations were observed between baseline concentrations of inflammatory biomarkers and DR presence, development, or progression over time. When comparing the highest quartile to the lowest quartile for a given biomarker in adjusted models, the hazard ratios (95% CI) for the development or progression of DR were: hsCRP 0.76 (0.55-1.03), IL-6 0.84 (0.62-1.14), TNF-α 1.03 (0.76-1.40), and CD163 0.84 (0.62-1.14). CONCLUSIONS: Our results indicate that systemic inflammatory biomarkers may not serve as reliable predictors for DR in early-stage type 2 diabetes. These findings contrast with prior cross-sectional studies suggesting a role for systemic low-grade inflammation in DR development. Inflammatory biomarkers. Diabetic retinopathy.