Relationship between levels of vascular endothelial growth factor in blood and severity of diabetic retinopathy

Abstract

Aim: The aim of the study was to establish the relationship between levels of vascular endothelial growth factor (VEGF) in blood and severity of diabetic retinopathy (DR). Background: The importance of VEGF in the pathogenesis of DR is evident from numerous studies demonstrating a significant increase in VEGF levels in samples obtained from the eye. However, a correlation between blood levels of VEGF and DR has not been conclusively proven or disproven. In this article, we demonstrate the relationship between blood levels of VEGF and the severity of DR. Materials and Methods: This is a hospital-based descriptive analytic study. The study population consisted of 75 Type 2 diabetic patients attending outpatient department for routine DR screening. After obtaining informed consent, 5 ml of blood was drawn from each patient and estimated for the levels of serum VEGF. The data thus obtained were correlated with the grade of DR. Additional parameters studied were duration of diabetes mellitus (DM), hemoglobin levels, blood urea, serum creatinine, fasting blood sugar (FBS) and random blood sugar (RBS), and hemoglobin A1c (HBA1c) levels. Statistical analysis used in this study was Chi-square test, Student's t-test, independent one sample t-test, and analysis of variance using SPSS software version. 19. Results: Overall mean VEGF levels for the study population of 75 diabetic patients were 577.01 ± 291.13 pg/ml. The average duration of DM in the study population was 7.2 years. The average hemoglobin level in the study population was 11.53 ± 2.00 g/dl. The mean urea levels in mg/dl of the whole population were 35.47 ± 25.80 mg/dl. The mean creatinine levels for the population were 1.42 ± 1.55 mg/dL. The mean RBS levels for the whole population were 228.95 ± 74.499 mg/dL. The mean FBS levels for the 75 patients were 165.87 ± 59.04 mg/dl. The mean HBA1c levels were 9.49 ± 2.37%. Conclusion: Levels of blood VEGF are elevated in diabetic patients regardless of whether they have DR or not. There is no statistically significant relationship between blood levels of VEGF and the severity of DR. Even though severe grades of DR showed more anemia, there is no statistically significant relationship between anemia and DR. The levels of urea and creatinine were elevated in the more severe grade of DR. VEGF, therefore, could present a potential treatment and preventive strategy for not only DR but also DM and its complications in general.