title: Association between the -634C/G polymorphisms of the vascular endothelial growth factor and retinopathy in type 2 diabetes: a meta-analysis.
abstract: OBJECTIVE
  To investigate the association of vascular endothelial growth factor (VEGF) -634C/G polymorphism with retinopathy in type 2 diabetes.
  
  
  METHODS
  8 studies with 1183 cases and 1057 controls were included. Allelic and genotypic comparisons between cases and controls were evaluated.
  
  
  RESULTS
  Our meta-analysis did not suggest a significant association of the -634C/G polymorphism with diabetic retinopathy (DR) and proliferative diabetic retinopathy (PDR) (P>0.05). The pooled odds ratios (ORs) for allelic frequency comparison, recessive model comparison, dominant model comparison, and additive model showed that the -634C/G polymorphism is significantly associated with nonproliferative diabetic retinopathy (NPDR): OR=1.61 [95% confidence interval (CI, 1.23, 2.10)], P=0.0005, P(heterogeneity)=0.38, OR=2.24 [95% CI (1.15, 4.39)], P=0.02, P(heterogeneity)=0.24, OR=1.87 [95% CI (1.01, 3.48)], P=0.05, P(heterogeneity)=0.16, and OR=2.91 [95% CI (1.33, 6.39)], P=0.008, P(heterogeneity)=0.26, respectively. However, in sensitivity analyses, we only detected a marginally significant association of the C allele with NPDR: OR=1.54 [95% CI (1.00, 2.39)], P=0.05, P(heterogeneity)=0.17.
  
  
  CONCLUSIONS
  Our meta-analysis does not support the association of the VEGF -634C/G polymorphism with DR and PDR. Significant association between this polymorphism and NPDR was detected in this meta-analysis. However, this association is not robust and could be due to chance.
authors.affiliation: Department of Geriatrics, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Number 88, Hangzhou, Zhejiang, PR China. zhaotongfeng@yahoo.com.cn
authors.forename: Tongfeng
authors.initials: T
authors.lastname: Zhao
authors.forename: Jiangpei
authors.initials: J
authors.lastname: Zhao
mesh_terms: D020121:5' Untranslated Regions / Q000235:genetics; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D003930:Diabetic Retinopathy / Q000235:genetics*; D056726:Genetic Association Studies; D006801:Humans; D008957:Models, Genetic; D020641:Polymorphism, Single Nucleotide; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics*
chemical_list: D020121:5' Untranslated Regions; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A