title: Elevated VEGF levels contribute to the pathogenesis of osteoarthritis.
abstract: BACKGROUND
  The aim of our meta-analysis is to understand the relationship between the pathogenesis of osteoarthritis and the expression levels of vascular endothelial growth factor (VEGF) in multiple disease tissues in osteoarthritis patients.
  
  
  METHODS
  The following electronic databases were searched, without language restrictions, to retrieve published studies relevant to VEGF and osteoarthritis: MEDLINE (1966 ~ 2013), the Cochrane Library Database (Issue 12, 2013), EMBASE (1980 ~ 2013), CINAHL (1982 ~ 2013), Web of Science (1945 ~ 2013) and the Chinese Biomedical Database (CBM) (1982 ~ 2013). Meta-analysis of the extracted data was performed using the STATA statistical software. Standardized mean difference (SMD) with its corresponding 95% confidence interval (95% CI) was calculated.
  
  
  RESULTS
  A total of 11 case-control studies, containing 302 osteoarthritis patients and 195 healthy controls, met our selection criteria for this meta-analysis. Our analyses of the data available from multiple disease tissues demonstrate that VEGF expression levels in osteoarthritis patients are significantly higher than healthy controls (SMD = 1.18, 95% CI: 4.91 ~ 9.11, P < 0.001). A subgroup analysis based on ethnicity revealed that both Asian and Caucasian osteoarthritis patients had higher levels of VEGF expression compared to their respective healthy counterparts (Asians: SMD = 5.49, 95% CI: 3.44 ~ 7.54, P < 0.001; Caucasians: SMD = 15.17, 95% CI: 5.21 ~ 25.13, P = 0.003; respectively). We also performed other subgroup analyses based on country, language and sample source, and the results showed that, in all these subgroups, osteoarthritis patients had higher levels of VEGF expression than healthy controls (all P > 0.05).
  
  
  CONCLUSIONS
  Our meta-analysis provides evidence that higher VEGF expression levels strongly correlate with the pathogenesis of osteoarthritis.
authors.affiliation: Department of Orthopedics, Shengjing Hospital of China Medical University, Sanhao Street No. 36, Heping District, Shenyang, 110004, P.R. China. yuanquanyq127@163.com.
authors.forename: Quan
authors.initials: Q
authors.lastname: Yuan
authors.affiliation: Department of Nephrology, The First Affiliated Hospital of China Medical University, Shenyang, 110001, P.R. China. cmu1h_sl@126.com.
authors.forename: Li
authors.initials: L
authors.lastname: Sun
authors.affiliation: Department of Orthopedics, Shengjing Hospital of China Medical University, Sanhao Street No. 36, Heping District, Shenyang, 110004, P.R. China. lijianjunljj127@163.com.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Li
authors.affiliation: Department of Orthopedics, Shengjing Hospital of China Medical University, Sanhao Street No. 36, Heping District, Shenyang, 110004, P.R. China. anchunhou127@163.com.
authors.forename: Chun-Hou
authors.initials: CH
authors.lastname: An
mesh_terms: D016022:Case-Control Studies; D006801:Humans; D010003:Osteoarthritis / Q000209:etiology* / Q000378:metabolism; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A