Evaluating peripheral blood inflammatory and metabolic biomarkers as predictors in diabetic retinopathy and diabetic macular edema

Purpose: To determine the correlation between serum inflammatory and metabolic biomarkers of patients with diabetic retinopathy (DR) and diabetic macular edema (DME). Methods: Serum samples were obtained from 100 diabetic patients. Patients were divided into three groups: group 1 (patients with no DR, n = 27), group 2 (DR with DME, n = 34), and group 3 (DR without DME, n = 39). Serum concentrations of C-reactive protein (CRP) and interleukin-6 (IL-6) were measured by quantitative turbidimetric immunoassay and sandwich chemiluminescence immunoassay, respectively. Metabolic parameters such as glycated hemoglobin (HbA1c), total cholesterol, low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglyceride (TG), serum creatinine, and blood urea were determined by automated analyzer om-360 after standardization. Results: The levels of IL-6 and CRP differed significantly in patients with DR and without DR (P < 0.001 and P = 0.045, respectively). We also found a positive correlation between IL-6 and CRP with the severity of DR. When DR patients with DME were compared to patients without DME, only IL-6 was observed to be significantly elevated (P < 0.001). None of the metabolic markers correlated significantly with DR and DME. Conclusion: Significantly raised levels of serum inflammatory biomarkers can be used to elucidate the significant role of inflammation in the pathogenesis of DR. Therefore, circulating biomarkers can serve as diagnostic and therapeutic predictors for monitoring the onset and progression of DR and DME.

Automated summary

This study investigated the correlation between serum inflammatory and metabolic biomarkers in patients with diabetic retinopathy (DR) and diabetic macular edema (DME). The results showed significant differences in the levels of IL-6 and CRP between patients with and without DR, with a positive correlation between IL-6 and CRP and the severity of DR. Only IL-6 was found to be significantly elevated in DR patients with DME compared to those without DME. None of the metabolic markers correlated significantly with DR and DME.