Table 5.

The effect of PEITC on changes of urinary concentrations of merpcaturic acid metabolites of benzene, acrolein and crotonaldehyde in smokers stratified by the glutathione S-transferase (GST) M1 and T1 genotype, The PEITC Intervention Study 2008–2013

Geometric mean
GST genotypeNPlaceboPEITC% difference (95% CI)PaPinteraction
GSTM1Benzene SPMA (pmol/mg creatinine)
 Null372.092.9943.1 (18.1–73.4)<0.0010.060
 Present453.123.4711.2 (−6.5–32.4)0.234
GSTT1
 Null190.831.4574.2 (33.9–126.6)<0.0010.006
 Present633.674.1412.7 (−2.4–30.4)0.108
GSTM1 and GSTT1
 Both null120.741.4595.4 (40.7–171.5)<0.0010.009
 One present322.643.3627.4 (4.3–55.6)0.020
 Both present383.844.076.1 (−11.6–27.5)0.526
GSTM1Acrolein HPMA (nmol/mg creatinine)
 Null378.0710.0524.6 (7.9–43.8)0.0050.179
 Present456.797.378.6 (−4.3–23.2)0.210
GSTT1
 Null198.0010.1226.6 (5.4–52.0)0.0220.320
 Present637.158.0012.0 (−0.1–25.6)0.057
GSTM1 and GSTT1
 Both null129.8413.0632.7 (5.9–66.2)0.0340.315
 One present326.908.2820.0 (1.8–41.3)0.038
 Both present387.047.537.0 (−6.9–22.9)0.347
GSTM1Crotonaldehyde HMPMA (nmol/mg creatinine)
 Null375.896.8015.4 (3.9–28.1)0.0090.027
 Present454.624.53−1.9 (−10.8–7.8)0.686
GSTT1
 Null195.346.5222.0 (5.3–41.4)0.0100.031
 Present635.105.151.0 (−6.8–9.5)0.808
GSTM1 and GSTT1
 Both null126.198.0429.8 (8.2–55.8)0.0060.017
 One present325.365.859.2 (−2.3–22.0)0.124
 Both present384.714.53−4.0 (−13.3–6.3)0.438
  • aTwo-sided P values were derived from the mixed models that test PEITC treatment effect on the change of urinary levels of biomarkers within each specific GST genotypes before and after PEITC intake.

    bTwo-sided P values were derived from the mixed models that test the interaction term between PEITC intake and GST genotype on the levels of urinary biomarkers.