TABLE 4.

Association between Combined Genotypes and Biomarkers of AA Exposure in Blood

Joint effects	No. of subjects	Mean ratio of GA-Hb/AA-Hb ± SE	p Value	Mean AA-Hb (pmol/g globin) ± SE	p Value	Mean GA-Hb (pmol/g globin) ± SE	p Value
GSTM1 and GSTT1
Ref	42	0.50 ± 0.03		49.70 ± 5.80		23.32 ± 2.62
GSTM1-null + GSTT1-null	7	0.71 ± 0.09	0.029*	79.60 ± 24.50	0.196	51.00 ± 12.80	0.006**
CYP2E1 and GSTM1
Ref	41	0.50 ± 0.03		51.10 ± 6.65		23.90 ± 3.10
CYP2E1 (Val/Val) + GSTM1-null	8	0.70 ± 0.09	0.022*	68.70 ± 15.57	0.175	44.71 ± 9.30	0.003**
CYP2E1, GSTM1, and GSTT1
Ref	44	0.52 ± 0.03		52.90 ± 6.65		25.10 ± 3.03
CYP2E1 (Val/Val) + GSTM1-null + GSTT1-null	5	0.74 ± 0.12	0.047*	63.40 ± 14.50	0.236	46.54 ± 13.74	0.033**
CYP2E1, GSTT1, and EPHX1
Ref.	45	0.51 ± 0.03		55.64 ± 6.61		27.20 ± 3.40
CYP2E1(Val/Val) + GSTT1-null + EPHX1 (Tyr/Tyr) + EPHX1 (His/Arg)	4	0.79 ± 0.11	0.018*	35.10 ± 2.90	0.385	28.10 ± 6.00	0.347

Note. *Significant associations between individuals with the combination variant of GSTM1 null and GSTT1 null, CYP2E1 (Val179Val) and GSTM1 null, CYP2E1 (Val/Val), GSTM1 null and GSTT1 null, and CYP2E1 (Val179Val), GSTT1 null, EPHX1 (Tyr113Tyr) and EPHX1 (His139Arg), and GA-Hb/AA-Hb ratio levels, p < 0.05. **Significant association between individuals with the combination variant of GSTM1 null and GSTT1 null, CYP2E1 (Val179Val) and GSTM1 null, and CYP2E1 (Val/Val), GSTM1 null and GSTT1 null, and GA-Hb adduct concentration, p < 0.05. The presence of the combination of the other genotypes was taken as the reference (or wild-type) group. The numbers in italics indicate the p-value for each calculated association.