An Updated Meta-Analysis: Risk Conferred by Glutathione S-Transferases (GSTM1 and GSTT1) Polymorphisms to Age-Related Cataract

Table 2

Subgroup analysis of the association between GSTM1 and GSTT1 polymorphisms and the risk of age-related cataract.

Groups	Number of studies	Statistical method	OR (95% CI)		References
GSTM1:
All studies	15	Random	1.161 (0.863–1.563)	0.324	[18–32]
Ethnicity:
Asian	6	Random	1.372 (0.786–2.396)	0.266	[18–23]
Caucasian	9	Random	1.053 (0.726–1.526)	0.158	[24–32]
Gender:
Female	5	Random	1.016 (0.444–2.324)	0.970	[22, 24, 27, 29, 30]
Male	5	Random	0.892 (0.582–1.365)	0.598	[22, 24, 27, 29, 30]
Subtype:
CC	6	Fixed	0.713 (0.598–0.850)	<0.001	[21, 22, 24–26, 29]
NC	5	Fixed	0.887 (0.685–1.148)	0.363	[21, 24–26, 29]
PSC	4	Fixed	1.042 (0.797–1.362)	0.765	[21, 24–26, 29]
MT	3	Random	0.937 (0.510–1.722)	0.834	[24, 26, 29]
Environmental risk factors:
Outdoor	2	Fixed	1.019 (0.511–2.034)	0.957	[28, 31]
Indoor	2	Random	2.062 (1.074–3.961)	0.030	[28, 31]
GSTT1:
All studies	9	Fixed	1.229 (1.057–1.429)	0.007	[21, 22, 24, 26, 27, 29–32]
Ethnicity:
Asian	2	Fixed	1.442 (1.137–1.830)	0.003	[21, 22]
Caucasian	7	Fixed	1.113 (0.830–1.492)	0.474	[24, 26, 27, 29–32]
Gender:
Female	5	Fixed	1.281 (0.972–1.687)	0.078	[22, 24, 27, 29, 30]
Male	5	Fixed	1.288 (0.977–1.698)	0.073	[22, 24, 27, 29, 30]
Subtype:
CC	5	Fixed	1.226 (0.999–1.504)	0.051	[21, 22, 24, 26, 29]
NC	4	Random	0.921 (0.524–1.617)	0.774	[21, 24, 26, 29]
PSC	4	Fixed	1.421 (1.043–1.936)	0.026	[21, 24, 26, 29]
MT	3	Random	1.209 (0.663–2.204)	0.535	[24, 26, 29]
GSTM1 null + GSTT1 null:	6	Fixed	1.069 (0.843–1.356)	0.581	[22, 24, 26, 27, 29, 30]
GSTM1 positive + GSTT1 positive:	6	Random	1.005 (0.658–1.536)	0.981	[22, 24, 26, 27, 29, 30]
GSTM1 positive + GSTT1 null:	5	Random	1.281 (0.840–1.954)	0.250	[22, 24, 27, 29, 30]

GSTM1: glutathione S-transferase M1; GSTT1: glutathione S-transferase T1. CC: cortical cataract; NC: nuclear cataract; PSC: posterior subcapsular cataract; MT: mixed type cataract. Fixed: a fixed effects model (Mantel-Haenszel method); Random: the random effects model (DerSimonian-Laird method).