Functional Vascular Endothelial Growth Factor −634G>C SNP Is Associated With Proliferative Diabetic Retinopathy A case-control study in a Brazilian population of European ancestry

OBJECTIVE —The purpose of this study was to evaluate the effect of the single nucleotide polymorphism (SNP) −634G>C at the 5′ regulatory region of the vascular endothelial growth factor (VEGF) in the risk of proliferative diabetic retinopathy (PDR) in the Brazilian population of European ancestry with type 2 diabetes. RESEARCH DESIGN AND METHODS —A case-control study was conducted in 501 type 2 diabetic patients of European ancestry. Patients underwent a standardized clinical, ophthalmological, and laboratory evaluation. Of these, 167 patients had PDR (case patients), and 334 were considered as control subjects (patients without PDR) for PDR. A reference population (110 individuals of European ancestry) was also evaluated. RESULTS —No evidence of association between −634G>C/VEGF and the presence of diabetic retinopathy or type 2 diabetes was observed ( P > 0.05). However, CC homozygous for the SNP −634G>C was significantly more frequent in patients with PDR (37 of 167; 22.2%) than in the corresponding control group (40 of 334; 12%) in accordance with a recessive model ( P = 0.003). This effect was further observed when creatinine, BMI, sex, duration of type 2 diabetes, HDL cholesterol, and systolic blood pressure were taken into account (odds ratio 1.9 [95% CI 1.01–3.79], P = 0.04). CONCLUSIONS —The presence of the allele −634C/VEGF in homozygosity is an independent risk factor for the development of PDR in type 2 diabetic patients of European ancestry.