title: Glutathione S-transferase M1 and P1 genotype, passive smoking, and peak expiratory flow in asthma.
abstract: OBJECTIVE
  Our purpose with this work was to assess the contribution of glutathione S-transferase gene variants to asthma susceptibility and pulmonary function in relation to tobacco smoke exposure in the home.
  
  
  METHODS
  Young individuals with asthma (age: 3-21 years; n = 504) were recruited through primary and secondary care throughout Tayside, Scotland (BREATHE Study). Spirometry was obtained on 407 individuals. Binary logistic regression and general linear modeling were used to explore phenotypic characteristics by genotype and tobacco smoke exposure status in younger children (3-12 years; n = 384) and teenagers and young adults (13-21 years; n = 120).
  
  
  RESULTS
  Three- to 12-year-olds with asthma, null for the GSTM1 gene or homozygous for the GSTP1Val105 allele, were overrepresented in the group exposed to environmental tobacco smoke. No differences in lung function values could be detected in this group. In contrast, 13- to 21-year-olds with the GSTM1-null genotype or homozygous for the GSTP1Val105 allele from smoking households were more likely to have a substantially lower percentage of predicted peak expiratory flow rates than those from nonsmoking households (83% vs 98%).
  
  
  CONCLUSIONS
  Three- to 12-year-olds who are null for GSTM1 or homozygous for the GSTP1Val105 allele are more susceptible to asthma associated with environmental tobacco smoke exposure than those with more intact glutathione S-transferase status. In the 13- to 21-year-olds, GSTM1-null status interacts with environmental tobacco smoke exposure to substantially reduce peak expiratory flow rate. The environmental tobacco smoke effect in GSTM1-null children with asthma could be cumulative over time, resulting in detrimental effects on peak expiratory flow rate in 13- to 21-year-olds with asthma.
authors.affiliation: Population Pharmacogenetics Group, Biomedical Research Centre, University of Dundee, Ninewells Hospital and Medical School, Dundee, Scotland, United Kingdom.
authors.forename: Colin N A
authors.initials: CN
authors.lastname: Palmer
authors.forename: Alex S F
authors.initials: AS
authors.lastname: Doney
authors.forename: Simon P
authors.initials: SP
authors.lastname: Lee
authors.forename: Inez
authors.initials: I
authors.lastname: Murrie
authors.forename: Tahmina
authors.initials: T
authors.lastname: Ismail
authors.forename: Donald F
authors.initials: DF
authors.lastname: Macgregor
authors.forename: Somnath
authors.initials: S
authors.lastname: Mukhopadhyay
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000483:Alleles; D001249:Asthma / Q000209:etiology / Q000235:genetics* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D005541:Forced Expiratory Volume; D017353:Gene Deletion; D020022:Genetic Predisposition to Disease; D005838:Genotype; D051549:Glutathione S-Transferase pi / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D005982:Glutathione Transferase / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D006801:Humans; D010366:Peak Expiratory Flow Rate; D010641:Phenotype; D017354:Point Mutation; D012606:Scotland; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D014797:Vital Capacity
chemical_list: D051549:Glutathione S-Transferase pi; D005982:Glutathione Transferase; D014028:Tobacco Smoke Pollution; C496556:GSTP1 protein, human