Association Of The Vascular Endothelial Growth Factor Polymorphism With Proliferative Diabetic Retinopathy

Objective: To study the relationship between polymorphism of vascular endothelial growth factor and diabetic retinopathySubjects and method: According to the standards of diabetic diagnosis and typing put forward by ADA in 1997, a total of 135 unrelated patients with type 2 diabetes were randomly recruited in this study. These patients were further divided into proliferative diabetic retinopathy (PDR)and nonproliferative diabetic retinopathy(NPDR) groups according to their result of fundus oculi fluorescence opacification. At the same time 60 healthy controls were selected from population for regular physical examination in our hospital. 6ml blood was taken from the elbow vein of each subject. Human genomic DNA was extracted by chloroform method Genotyping for the vascular endothelial growth factor -460 polymorphisms was carried out by PCR-RFLP analysis(polymerase chain reaction- restriction fragment length polymorphism).Clinical characteristics such as 24h microalbuminuria, HbA1c, BMI, BUN,TC,TG etc were measured and calculated meanwhile. All data was tested the normality. Chi-square analysis was used to test whether VEGF genotype distribution followed the Hardy-Weinberg equilibrium. Normally distributed data was demonstrated using means±SD( x±s).Non-normally distributed data was demonstrated using median(quartile range). Measurement data was compared using t or t'-test. Numeration data was compared using Chi-square analysis. Risk factors for type 2 diabetic proliferative diabetic retinopathy using multiple logistic regression analysis.Results: (1).Type 2 diabetic patients had higher HbA1c,BMI,BUN,TG and Cr level than normal controls(p<0.001).The paients with PDR have a higher level of HbA1c than those with NPDR,and suffered with diabetes for longer(p<0.001). (2). VEGF-460 CC and C allele frequency were significantly increased in patients with PDR than those with NPDR and controls(p<0.05 or p<0.01).(3). Morbidity rate was significantly increased in subjects with the VEGF-460 CC genotype compared with CT and TT genotype(p<0.01). The odds ratio (OR) of PDR for the CC genotype to the TT genotype was 4.5. (4). Logistic regression analysis revealed that the VEGF-460C/T polymorphism was independent risk factors of PDR.Conclusion:. VEGF-460C/T genetic polymorphism was associated with PDR. C allele is probably a susceptible gene of PDR.