The association between VEGF -634C/G polymorphisms and osteonecrosis of femoral head: a meta-analysis.

The polymorphism of the vascular endothelial growth factor (VEGF) -634C/G has been correlated with susceptibility to osteonecrosis of the femoral head (ONFH). The aim of this study was to derive a more precise estimation of the relationship between the VEGF -634C/G polymorphism and ONFH by performing a meta-analysis. We searched articles indexed in Pubmed, OVID and Web of Science published up to January 2015 that met our predefined criteria. The strength of the association between VEGF -634C/G polymorphism and ONFH risk was assessed by an odds ratio (OR) with the corresponding 95% CI. Three eligible studies involving 692 cases and 875 controls were identified. Overall, pooled analysis indicated a significant association between VEGF -634C/G polymorphism and ONFH risk (for C vs. G: OR=1.141, 95% CI 1.055-1.235, P=0.001; for CC vs. GG: OR=1.345, 95% CI 1.124-1.610, P=0.001; for CG vs. GG: OR=1.106, 95% CI 1.018-1.202, P=0.017; for CG+CC vs. GG: OR=1.104, 95% CI 1.035-1.177, P=0.003; for CC vs. GG+ CG: OR=1.294, 95% CI 1.051-1.593, P=0.015). No evidence of publication bias was observed. In conclusion, this meta-analysis suggested that polymorphism of VEGF -634C/G was a risk factor for ONFH. This finding needs further confirmation by trans-regional multicenter study with large sample in different ethnic populations, such as Caucasian and Austroloid.