Table 4—

Analysis of the interaction between genetic polymorphisms of xenobiotic-metabolising enzymes and their association with COPD severity

PolymorphismFEV1OR# (95% CI)
<35% pred≥35% pred
Subjects n65119
mEPHX exon 3
 Tyr113/Tyr1135 (7.7)25 (21.0)1
 Tyr113/His11319 (29.2)63 (52.9)1.9 (0.5–7.0)
 His113/His11341 (63.1)31 (26.1)7.5 (2.1–26.3)**
 His113 allele frequency0.770.53
mEPHX exon 4
 His139/His13946 (70.8)91 (76.5)0.9 (0.1–7.8)
 His139/Arg13917 (26.2)27 (22.7)0.8 (0.1–4.2)
 Arg139/Arg1392 (3.0)1 (0.8)1
 Arg139 allele frequency0.160.12
GSTM1
 Non-null genotype10 (15.4)56 (47.1)1
 Null genotype55 (84.6)63 (52.9)5.6 (2.2–13.9)**
GSTT1
 Non-null genotype32 (49.2)53 (44.5)1
 Null genotype33 (50.8)66 (55.5)0.9 (0.4–1.7)
GSTP1
 Ile105/Ile10532 (49.2)64 (53.8)0.6 (0.1–2.4)
 Ile105/Val10528 (43.1)51 (42.9)0.4 (0.1–1.5)
 Val105/Val1055 (7.7)4 (3.3)1
 Ile105 allele frequency0.700.75
  • Data are presented as n (%) unless otherwise indicated

  • FEV1: forced expiratory volume in one second

  • % pred: percentage of the predicted value

  • OR: odds ratio

  • CI: confidence interval

  • mEPHX: microsomal epoxide hydrolase

  • Tyr: tyrosine

  • His: histidine

  • Arg: arginine

  • GST: glutathione S-transferase

  • Ile: isoleucine

  • Val

  • valine

  • #: adjusted for age, sex and cumulative cigarette consumption

  • **: p<0.01