title: Meta-analyses on suspected chronic obstructive pulmonary disease genes: a summary of 20 years' research.
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) is a complex disorder with high mortality worldwide. Studies on the role of candidate genes and their polymorphisms in COPD development have so far produced ambiguous results.
  
  
  OBJECTIVE
  The aim of this study was to reveal the role of COPD candidate genes using data collected in previous research.
  
  
  METHODS
  We performed meta-analyses on 20 polymorphisms in 12 genes, after searching the PubMed and Embase databases for publications on COPD. These genes involve three main pathways associated with COPD development: the inflammatory, protease-antiprotease balance, and antioxidant pathways.
  
  
  RESULTS
  We obtained significant results for three TGFB1 polymorphisms, although these were based only on a few studies. The IL1RN VNTR polymorphism increases the risk for COPD (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.09-2.65), whereas the TNFA -308 G/A polymorphism does so only in Asian populations (OR, 2.01; 95% CI, 1.21-3.31). The GSTP1 I105V polymorphism was protective for COPD in Asian populations only (OR, 0.69; 95% CI, 0.56-0.85).
  
  
  CONCLUSIONS
  These results demonstrate the importance of ethnicity in identifying specific COPD genes.
authors.affiliation: Department of Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
authors.forename: Joanna
authors.initials: J
authors.lastname: Smolonska
authors.forename: Cisca
authors.initials: C
authors.lastname: Wijmenga
authors.forename: Dirkje S
authors.initials: DS
authors.lastname: Postma
authors.forename: H Marike
authors.initials: HM
authors.lastname: Boezen
mesh_terms: D000975:Antioxidants; D044466:Asian People / Q000208:ethnology / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000208:ethnology / Q000235:genetics*; D006801:Humans; D007249:Inflammation / Q000208:ethnology / Q000235:genetics; D018384:Oxidative Stress / Q000235:genetics; D010447:Peptide Hydrolases / Q000235:genetics; D011110:Polymorphism, Genetic / Q000235:genetics; D011480:Protease Inhibitors; D029424:Pulmonary Disease, Chronic Obstructive / Q000208:ethnology / Q000235:genetics*
chemical_list: D000975:Antioxidants; D011480:Protease Inhibitors; D010447:Peptide Hydrolases