Correlation of vascular endothelial growth factor plasma levels and glycemic control in patients with diabetic retinopathy

Purpose: To determine whether glycemic control of patients with diabetic retinopathy (DR) due to type 2 diabetes was related to VEGF plasma levels. Methods: The prospective study included 30 patients with DR due to type 2 diabetes. Retinopathy was classified according to the international clinical DR disease severity scale. The concentrations of VEGF in the blood plasma were measured by ELISA. Glycosylated hemoglobin (HbA1c) was assessed all patients. Results were reported as DCCT/NGSP-HbA1c (%) values. Results: The median plasma level of VEGF was 34.5 (range 15-217) pg/ml. Median HbA1c was 7.5 (range 5.3-10.6). The highest individual plasma VEGF measurements were found in patients with severe non-proliferative DR. HbA1c levels revealed a significant correlation with plasma VEGF concentrations (r=0.573, p=0.001). Age (r=0.097, p=0.611), gender (r=-0.315, p=0.09) and severity of DR (r=0.256, p=0.172) were with no significant relationship to the VEGF measurements. Conclusion: Poor glycemic control is positively correlated with increased levels of plasma VEGF in patients with type 2 diabetes. As normalization of HbA1c is one of the most effective ways to prevent progression of DR and VEGF has been to shown to be clearly implicated in the development of DR, it affirms the importance of glycemic control in patients with DR.