Table 3.

Joint effects of GST genotype and drinking water level of arsenic on Case Status

				Overall Joint Effects				Joint Effects Stratified on Exposure		Joint Effects Stratified on Genotype
	As Level of Well	Controls (N)	Cases (N)	OR (95%CI)	p-value	ICR	95%CL	OR (95%CI)	p-value	OR (95%CI)	p-value
GSTT1
Null	low	85	52	1.0				1.0		1.0
Wildtpe	low	376	272	1.62 (1.06–2.49)	0.03			1.62 (1.06–2.49)	0.03	1.0
null	high	27	48	3.16 (1.71–5.85)	0.0002			1.0		3.16 (1.71–5.85)	0.0002
Wildtpe	high	106	222	3.64 (2.31–5.74)	<0.0001			1.15 (0.68–1.94)	0.60	2.24 (1.69–2.98)	<0.0001
						0.94	(-2.08–1.83)
GSTM1
Null	low	189	126	1.0				1.0		1.0
Wildtype	low	272	198	1.02 (0.74–1.40)	0.91			1.02 (0.74–1.40)	0.91	1.0
Null	high	55	117	2.62 (1.77–3.90)	<0.0001			1.0		2.62 (1.77–3.90)	<0.0001
Wildtype	high	78	151	2.24 (1.56–3.22)	<0.0001			0.85 (0.57–1.29)	0.85	2.20 (1.57–3.09)	<0.0001
						1.02	(-2.40–1.57)
GSTP1
AA	low	246	180	1.0				1.0		1.0
AG	low	184	110	0.81 (0.58–1.14)	0.23			0.81 (0.58–1.14)	0.23	1.0
GG	low	26	32	2.32 (1.31–4.09)	0.004			2.32 (1.31–4.09)	0.004	1.0
AA	high	67	138	2.27 (1.60–3.22)	<0.0001			1.0		2.27 (1.60–3.22)	<0.0001
AG	high	52	108	2.49 (1.69–3.68)	<0.0001	0.85	(-2.13–1.51)	1.10 (0.72–1.69)	0.67	3.06 (2.01–4.66)	<0.0001
GG	high	10	20	2.38 (1.11–5.13)	0.03	1.68	(-2.15–1.83)	1.04 (0.48–2.31)	0.90	1.03 (0.41–2.55)	0.95

All models adjusted for liters of liquid/day, age, gender, educational status, BMI, chewing tobacco, betel nut use, smoking status, and previous well use