Table 1.

Characteristics of the case–control studies included in meta-analysis.

First author	Year	Country	Ethnicity	Gender	Case	Control	Case	Control	Genotyping
					number (n)	number (n)	AA (A)	AG + GG (G)	AA (A)	AG + GG (G)	Method
Kurth	1993	USA	Caucasian	M, F	64	177	25	39	36	141	PCR-SSCP
Morimoto	1995	Japan	Asian	M, F	83	76	60	23	54	22	PCR-SSCP
Costa	1997	USA	Caucasian	M, F	62	79	26	36	23	56	PCR-SSCP
Hwang	1997	China	Asian	M, F	65	108	49	16	76	32	PCR-SSCP
Checkoway	1998	USA	Caucasian	M, F	82	118	52	30	58	60	PCR-SSCP
Mellick	1999	Australia	Caucasian	M, F	80	110	30	50	36	74	PCR-SSCP
Shao	2000	China	Asian	M, F	126	136	66	65	62	74	PCR-SSCP
Wu	2001	China	Asian	M, F	220	191	37	183	17	174	PCR-SSCP
Hernán	2002	USA	Caucasian	M, F	214	449	86	128	196	253	Allele-specific PCR
Kelada	2002	USA	Caucasian	M, F	186	296	106	80	138	158	PCR-SSCP
Tan	2003	Singapore	Asian	M, F	230	241	171	59	176	65	PCR-SSCP
Jiang	2004	China	Asian	M, F	266	154	207	59	114	40	PCR-SSCP
Białecka	2005	Poland	Caucasian	M, F	210	152	100	110	63	89	PCR-SSCP
Singh	2008	India	Asian	M, F	70	100	30	37	33	37	PCR-SSCP
Gu	2010	China	Asian	M, F	176	354	153	23	323	31	DHPLC
Wang	2010	China	Asian	M, F	125	66	88	37	34	32	PCR-SSCP
Kiyohara	2011	Japan	Asian	M, F	238	369	192	46	273	96	PCR-SSCP
Li	2011	China	Asian	M, F	166	170	111	55	103	67	PCR-RFLP
Torkaman-Boutorabi	2012	Iran	Caucasian	M, F	103	70	75	28	44	26	PCR-RFLP
Zeng	2012	China	Asian	M, F	95	104	67	28	71	33	PCR-RFLP

M: male, F: female, MF: male and female, PCR: polymerase chain reaction, SSCP: single-stranded conformational polymorphism, RFLP: restriction fragment length polymorphism, DHPLC: denaturing high-performance liquid chromatography.