Table 4.

CBMN frequency (‰) in coke-oven and non–coke-oven workers by genotypes of phase II metabolic enzymes

GenotypesNon–coke-oven workers
Coke-oven workers
P*
nMean ± SDPnMean ± SDP
mEH exon 3
    Tyr/Tyr224.0 ± 3.4Reference5211.3 ± 6.4Reference<0.01
    Tyr/His254.2 ± 4.60.62317.9 ± 5.10.04<0.01
    His/His193.7 ± 2.10.71588.9 ± 7.2<0.01<0.01
    Tyr/His-His/His444.0 ± 3.70.90898.5 ± 6.5<0.01<0.01
mEH exon 4
    His/His573.9 ± 2.6Reference1069.2 ± 6.6Reference<0.01
    His/Arg84.8 ± 4.00.323410.2 ± 6.50.570.02
    Arg/Arg14.00.82118.00.11
    His/Arg-Arg/Arg94.7 ± 3.70.313510.5 ± 6.50.420.01
GSTM1
    Non-null413.7 ± 3.4Reference748.9 ± 6.8Reference<0.01
    Null254.4 ± 4.00.406710.2 ± 6.30.12<0.01
GSTT1
    Non-null363.8 ± 3.1Reference718.9 ± 5.8Reference<0.01
    Null304.2 ± 4.20.827010.2 ± 7.30.47<0.01
GSTP1
    Ile/Ile394.7 ± 4.2Reference849.4 ± 6.8Reference<0.01
    Ile/Val253.1 ± 2.10.35519.1 ± 6.20.56<0.01
    Val/Val20§0.01615.0 ± 5.80.010.07
    Ile/Val-Val/Val272.9 ± 2.20.18579.7 ± 6.30.85<0.01
NQO1
    CC253.3 ± 2.7Reference489.4 ± 7.3Reference<0.01
    CT265.0 ± 4.50.15619.7 ± 6.50.36<0.01
    TT153.4 ± 2.90.83329.4 ± 5.70.36<0.01
    CT-TT414.4 ± 4.00.26939.6 ± 6.20.29<0.01
  • * Mann-Whitney U tests for the differences in CBMN frequencies between coke-oven workers and non–coke-oven workers by each genotype.

  • Multivariate analysis of covariance tests for differences in ln-transformed CBMN data between genotypes with adjustment for urinary 1-OHP, age, sex, and cigarettes per day in coke-oven workers and non–coke-oven workers separately.

  • Reference group for comparisons of ln-transformed CBMN data between genotypes.

  • § P = 0.05, compared with the GSTP1 Ile/Val genotype.

  • P = 0.02, compared with the GSTP1 Ile/Val genotype.