title: Significant association between asthma risk and the GSTM1 and GSTT1 deletion polymorphisms: an updated meta-analysis of case-control studies.
abstract: Polymorphisms in GSTM1 and GSTT1 may be associated with asthma risk, yet several studies and meta-analyses have reported inconclusive results. Therefore, an updated meta-analysis was conducted. Literature searches were performed using the Pubmed, Embase and Web of Science databases until October 2012. Variant 'null' genotype was compared with wild-type 'present' in the pooled data. All statistical analyses were performed using STATA 11.0. A total of 26 case-control studies were suitable for inclusion in the meta-analysis. In the overall population, a significant association was found for both the GSTM1 (odds ratio (OR) = 1.452; 95% confidence interval (CI): 1.192-1.770) and GSTT1 polymorphism (OR = 1.792; 95% CI:1.293-2.483). For subgroup analysis by age, GSTM1 significantly increased risk for both children (OR = 1.368; 95% CI: 1.051-1.781) and adults (OR = 1.859; 95% CI: 1.183-2.921). For GSTT1, a significant association was only found in the adult population (OR = 2.312; 95%CI: 1.204-4.439). Based on subgroup analysis by ethnicity, a significant association for GSTM1 was found in Europe (OR = 1.303; 95% CI: 1.018-1.667), Africa (OR = 2.175; 95%CI: 1.560-3.031) and Latin America (OR = 2.265; 95%CI: 1.375-3.729). For GSTT1, significantly increased risk was found only for Asian (OR = 2.105; 95% CI: 1.101-4.025) and Russian (OR = 2.747; 95% CI: 1.071-7.046) populations. This meta-analysis provides evidence that GSTM1 and GSTT1 polymorphisms may be risk factors for asthma.
authors.affiliation: Department of Respiratory Medicine, First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.
authors.forename: Siqiao
authors.initials: S
authors.lastname: Liang
authors.forename: Xuan
authors.initials: X
authors.lastname: Wei
authors.forename: Chen
authors.initials: C
authors.lastname: Gong
authors.forename: Jinmei
authors.initials: J
authors.lastname: Wei
authors.forename: Zhangrong
authors.initials: Z
authors.lastname: Chen
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Chen
authors.forename: Zhibo
authors.initials: Z
authors.lastname: Wang
authors.forename: Jingmin
authors.initials: J
authors.lastname: Deng
mesh_terms: D001249:Asthma / Q000453:epidemiology / Q000235:genetics*; D016022:Case-Control Studies; D017353:Gene Deletion; D020022:Genetic Predisposition to Disease / Q000235:genetics; D005982:Glutathione Transferase / Q000235:genetics*; D006801:Humans; D016017:Odds Ratio; D011110:Polymorphism, Genetic / Q000235:genetics*; D012307:Risk Factors
chemical_list: D005982:Glutathione Transferase; C413545:glutathione S-transferase T1