title: Matrix metalloproteinase-9 -1562C/T promoter polymorphism confers risk for COPD: a meta-analysis.
abstract: BACKGROUND
  The role of matrix metalloproteinase (MMP) gene polymorphisms in the development of chronic obstructive pulmonary disease (COPD) has been reported with inconsistent results. This meta-analysis was performed to assess the association of MMP-1 -1607G/GG and MMP-9 -1562C/T promoter polymorphisms with COPD susceptibility.
  
  
  METHODS
  Published case-control studies from Pubmed and China National Knowledge Infrastructure (CNKI) databases were retrieved. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated.
  
  
  RESULTS
  A total of fourteen case-control studies were included in this meta-analysis. Pooled effect size showed an association of MMP-9 -1562 C/T with the risk of COPD (dominant model: TT+CT vs CC; OR: 1.46; 95% CI: 1.02-2.08; p = 0.04). However, no correlation with COPD was revealed in MMP-1 -1607G/GG polymorphism. When stratified by ethnicity, results indicated MMP-1 -1607G/GG (recessive model: G/G vs G/GG+GG/GG; OR: 1.20; 95% CI: 1.01-1.44; p = 0.04) and MMP-9 -1562 C/T (dominant model; OR: 1.66; 95% CI: 1.01-2.71; p = 0.04) were correlated with COPD susceptibility among Caucasians and Asians respectively. According to source of controls, significant association of MMP-9 -1562 C/T (additive model: T vs C; OR:1.71, 95% CI: 1.42-2.07; p<0.00001, and dominant model; OR: 1.92; 95% CI: 1.34-2.76; p = 0.0004) with COPD susceptibility was revealed in the subgroup with smoker-based controls. However, in the aforementioned risk estimates, only the association of MMP-9 -1562 C/T (additive and dominant models) with the risk of COPD in the subgroup with smoker-based controls persisted significantly after Bonferroni correction for multiple testing. Moreover, after excluding the studies without Hardy-Weinberg equilibrium and/or with small sample size, the pooled results were robust and no publication bias was found in this study.
  
  
  CONCLUSIONS
  This meta-analysis suggests, when using healthy smokers as controls, MMP-9 -1562 C/T, but not MMP-1 -1607 G/GG polymorphism is associated with the risk of COPD.
authors.affiliation: Division of Pulmonary Diseases, State Key Laboratory of Biotherapy of China, West China Hospital, West China School of Medicine, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Chen
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.forename: Lian
authors.initials: L
authors.lastname: Liu
authors.forename: Yongchun
authors.initials: Y
authors.lastname: Shen
authors.forename: Chun
authors.initials: C
authors.lastname: Wan
authors.forename: Fuqiang
authors.initials: F
authors.lastname: Wen
mesh_terms: D016022:Case-Control Studies; D006801:Humans; D020780:Matrix Metalloproteinase 9 / Q000235:genetics*; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D029424:Pulmonary Disease, Chronic Obstructive / Q000235:genetics*; D012907:Smoking / Q000235:genetics
chemical_list: D020780:Matrix Metalloproteinase 9
references.citation: Circulation. 2003 Apr 1;107(12):1579-85
references.pmid: 12668489
references.citation: Zhonghua Liu Xing Bing Xue Za Zhi. 2005 Nov;26(11):907-10
references.pmid: 16676616
references.citation: Genetika. 2008 Feb;44(2):242-9
references.pmid: 18619044
references.citation: Eur Respir J. 2012 Jan;39(1):197-209
references.pmid: 21920892
references.citation: Am J Respir Crit Care Med. 2005 Dec 1;172(11):1378-82
references.pmid: 16126934
references.citation: Genet Mol Res. 2009 Aug 25;8(3):1028-34
references.pmid: 19731200
references.citation: Science. 1997 Sep 26;277(5334):2002-4
references.pmid: 9302297
references.citation: Int J Chron Obstruct Pulmon Dis. 2006;1(3):267-78
references.pmid: 18046864
references.citation: Cancer Res. 1998 Dec 1;58(23):5321-5
references.pmid: 9850057
references.citation: Biochem Genet. 2009 Aug;47(7-8):591-601
references.pmid: 19507017
references.citation: Am J Respir Crit Care Med. 2011 Oct 15;184(8):873-80
references.pmid: 21799071
references.citation: Chin Med J (Engl). 2004 Oct;117(10):1481-4
references.pmid: 15498369
references.citation: BMC Med Genet. 2010 Jan 15;11:7
references.pmid: 20078883
references.citation: Thorax. 2012 Mar;67(3):271-3, 280
references.pmid: 21856699
references.citation: Biochem Biophys Res Commun. 2001 Nov 23;289(1):116-9
references.pmid: 11708786
references.citation: Postgrad Med J. 2007 Apr;83(978):244-50
references.pmid: 17403951
references.citation: Respiration. 2010;80(2):133-8
references.pmid: 20160424
references.citation: Circulation. 1999 Apr 13;99(14):1788-94
references.pmid: 10199873
references.citation: Am J Respir Crit Care Med. 1997 Jul;156(1):240-7
references.pmid: 9230755