Clinical Research Between The Content Of Vascular Endothelial Growth Factor. Leptin And Diabetic Retinopathy

Background: Diabetic retinopathy (DR) is one of the leading cause of new blindness in adult patients. Retinal neovascularization is a characteristic feature of diabetic retinopathy. In recent years, it's believed that DR results from cooperation of growth factors. In normal state, there was equilibrium between angiogenic growth factors and anti-angiogenic growth factors in retinal tissue. Once the balance is broken, the elevated angiogenic growth factors may contribute to the deposition to the expression of anti-angiogenic growth factors, which causes neovascularization and diabetic retinopathy. Vascular endothelial growth factor (VEGF) is a glycoprotein which functions are specific endothelial mitogen-promoting angiogenesis and potent vascular permeability. It is viewed that many growth factor play their role of prompting angiogenesis through VEGF. Leptin, an adipocyte-derived hormone, stimulates endothelial proliferation and angiogenesis. The present study suggests that leptin plays a critical role in the progression of ischemia-induced retinal neovascularization by induction of VEGF. This study was designed to measure the concentration of serum vascular endothelial growth factor, leptin in diabetes, control and analyze relationship among them and between them and other factors so as to investigate the roles they play in the occurrence and progression of diabetic retinopathy.Methods: Seventy–five patients with DM were divided into three groups: Non-diabetic retinopathy (NDR), background DR (BDR) and proliferative DR (PDR). The contents of VEGF, LP were measured by double antibody sandwich enzyme-linked assay and radioimmunoassay by turns. The relationship between these factors and age, duration of diabetes, serum lipid, fasting blood glucose(FBG), Insulin sensibility index(ISI), glucosilated hemoglobin (HbA1c), Fructosamine (FA) were also analysed. These data were analysed by SPSS for windows of 11.5.Results:1. The value of serum VEGF in each group(1) Serum VEGF in three diabetic groups increased significantly more than that in the control (P<0.001).(2) VEGF in BDR group was significantly higher than that in NDR group and PDR group (P<0.01).(3) VEGF in PDR group was higher than that in NDR (P<0.05). But there was no difference between the two groups.2. The content of LP in each group The content of LP had the intrence to increase in NDR, BDR, PDR. PDR was higher than those in control (P<0.05). But there was no difference between other groups.