title: Association of Matrix Metalloproteinase-9 Gene -1562C/T Polymorphism with Essential Hypertension: A Systematic Review and Meta-Analysis Article.
abstract: BACKGROUND
  Matrix metalloproteinase-9 (MMP-9) gene -1562C/T polymorphism could regulate its expression level and thus affected people's predisposition to essential hypertension. However, related studies yielded inconsistent or contradictory results.
  
  
  METHODS
  To evaluate the association of MMP-9 -1562C/T polymorphism with essential hypertension, we performed a meta-analysis by combining all available independent case-control studies (n=6).A systematic literature search of PubMed, Web of Science, Scopus and CNKI (Chinese National Knowledge Infrastructure) databases was conducted by two researchers independently for all relevant articles published before March 2015.
  
  
  RESULTS
  MMP-9 -1562C/T polymorphism was associated with essential hypertension under the allelic model (T vs.C, OR=1.36, 95% CI=1.17-1.59, P<0.0001). Subsequent sensitivity analysis confirmed the stability of the results. Such association was also observed in the dominant (TT+CT vs. CC, OR=1.30, 95% CI=1.10-1.54, P=0.002) and co-dominant (CT vs. TT+CC, OR=1.27, 95% CI=1.05-1.53, P=0.01) models but not in the recessive model (TT vs. CT+CC, OR=1.30, 95% CI=0.50-3.36, P=0.59).
  
  
  CONCLUSIONS
  MMP-9 -1562C/T polymorphism was associated with the risk of essential hypertension.
authors.affiliation: School of Pharmacy, Shanghai University of Medicine & Health Sciences, Shanghai, China.
authors.forename: Wenchao
authors.initials: W
authors.lastname: Yang
authors.affiliation: Shanghai Pudong New District Zhoupu Hospital, Shanghai, China.
authors.forename: Jiaojiao
authors.initials: J
authors.lastname: Lu
authors.affiliation: Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Yang
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China.
authors.forename: Jinjin
authors.initials: J
authors.lastname: Zhang
keywords: Essential hypertension; MMP-9; Meta-analysis