title: Association between the plasminogen activator inhibitor-1 4G/5G polymorphism and risk of venous thromboembolism: a meta-analysis.
abstract: BACKGROUND
  The plasminogen activator inhibitor-1 (PAI-1) 4G/5G polymorphism was considered to be associated with risk of venous thromboembolism (VTE), while evidence remains inadequate. To provide a more accurate estimation of this relationship, we performed an updated meta-analysis of all eligible studies.
  
  
  METHODS
  A systematical search was performed in PubMed, EMBASE, Wanfang, China National Knowledge Infrastructure (CNKI) and Cqvip databases to identify relevant studies published before March 6(th) 2014. The odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using the fixed/random-effects model using Review Manager 5.1 and STATA 12.0.
  
  
  RESULTS
  A total of 34 studies with 3561 cases and 5693 controls were analyzed. Overall, significant association between the PAI-1 4G/5G variant and VTE risk in total population (dominant model: OR=1.32, 95%CI: 1.13-1.54) was observed. And this variant was also related to the deep vein thrombosis risk (dominant model: OR=1.60, 95%CI: 1.24-2.06, P=0.0003). In the subgroup analyses on ethnicity, significant results were obtained in both Asians (dominant model: OR=2.08, 95%CI: 1.29-3.35, P=0.003) and Caucasians (dominant model: OR=1.31, 95%CI: 1.10-1.56, P=0.003). However, no significant association was found in patients with provoked VTE. In terms of subgroup analyses on co-existence of other thrombotic risk factors, the PAI-1 4G/5G polymorphism was significantly associated with VTE risk in patients with factor V Leiden mutation (dominant model: OR=1.72, 95%CI: 1.17-2.53), but not in patients with cancer or surgery.
  
  
  CONCLUSIONS
  Our findings demonstrate the role of PAI-1 4G/5G polymorphism being a risk candidate locus for VTE susceptibility, especially in patients with other genetic thrombophilic disorders.
authors.affiliation: West China Medical School of Sichuan University, Chengdu, Sichuan Province, China.
authors.forename: Jiarong
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Respiratory Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan, China.
authors.forename: Chengdi
authors.initials: C
authors.lastname: Wang
authors.affiliation: West China Medical School of Sichuan University, Chengdu, Sichuan Province, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Chen
authors.affiliation: West China Medical School of Sichuan University, Chengdu, Sichuan Province, China.
authors.forename: Chi
authors.initials: C
authors.lastname: Shu
authors.affiliation: West China Medical School of Sichuan University, Chengdu, Sichuan Province, China.
authors.forename: Xiaojiang
authors.initials: X
authors.lastname: Guo
authors.affiliation: West China Medical School of Sichuan University, Chengdu, Sichuan Province, China; Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.
authors.forename: Yazhou
authors.initials: Y
authors.lastname: He
authors.affiliation: Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, Sichuan Province, P.R China. Electronic address: Yanhong_zhou2013@163.com.
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D005819:Genetic Markers / Q000235:genetics; D020022:Genetic Predisposition to Disease / Q000453:epidemiology* / Q000235:genetics*; D006801:Humans; D015994:Incidence; D009154:Mutation / Q000235:genetics; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012307:Risk Factors; D054556:Venous Thromboembolism / Q000453:epidemiology* / Q000235:genetics*
chemical_list: D005819:Genetic Markers; D017395:Plasminogen Activator Inhibitor 1; C051321:SERPINE1 protein, human
keywords: 4G/5G polymorphism; Genetic susceptibility; Meta-analysis; PAI-1; Venous thromboembolism