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

Rong-Feng Liao,Min-Jie Ye,Dong-Qing Ye,Cai-Yuan Liu

doi:10.1155/2015/103950

Abstract

Purpose. To study the effects of glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) polymorphisms on age-related cataract (ARC). Methods. After a systematic literature search, all relevant studies evaluating the association between GSTs polymorphisms and ARC were included. Results. Fifteen studies on GSTM1 and nine studies on GSTT1 were included in this meta-analysis. In the pooled analysis, a significant association between null genotype of GSTT1 and ARC was found (OR = 1.229, 95% CI = 1.057–1.429, and P = 0.007). In subgroup analysis, the association between cortical cataract (CC) and GSTM1 null genotype was statistically significant (OR = 0.713, 95% CI = 0.598–0.850, and P < 0.001). In addition, GSTM1 null genotype was significantly associated with ARC causing risk to individuals working indoors and not individuals working outdoors. The association between GSTT1 null genotype and risk of ARC was statistically significant in Asians (OR = 1.442, 95% CI = 1.137–1.830, and P = 0.003) but not in Caucasians. Conclusions. GSTM1 positive genotype is associated with increased risk of CC and loses the protective role in persons who work outdoors. Considering the ethnic variation, GSTT1 null genotype is found to be associated with increased risk of ARC in Asians but not in Caucasians.

Highlights

Cataract is one of the most common causes of visual impairment and blindness all over the world. 80% of cataract is age-related cataract (ARC), which is classified as cortical cataract (CC), nuclear cataract (NC), or posterior subcapsular cataract (PSC), according to the location of the opacity in the lens [1, 2]
By gender, we found that glutathione S-transferase M1 (GSTM1) null genotype was not associated with ARC in female or male group (OR = 1.016, 95% confidence interval (CI) = 0.444–2.324, and P = 0.970; odds ratio (OR) = 0.892, 95% CI = 0.582–1.365, and P = 0.598, resp.)
By the work place, we found that the association between GSTM1 null genotype and ARC was statistically significant in the indoor subjects but not in the outdoor subjects (OR = 2.062, 95% CI = 1.074–3.961, and P = 0.030, Figure 5(a); OR = 1.019, 95% CI = 0.511–2.034, and P = 0.957, Figure 5(b))

Summary

Introduction

Cataract is one of the most common causes of visual impairment and blindness all over the world. 80% of cataract is age-related cataract (ARC), which is classified as cortical cataract (CC), nuclear cataract (NC), or posterior subcapsular cataract (PSC), according to the location of the opacity in the lens [1, 2]. The pathogenesis of ARC is not fully understood, many epidemiologic studies have noted that oxidative stress and genetic factors may play major roles in the development of ARC [3]. There are many cellular defense mechanisms that protect the human lens from oxidative damage. The glutathione S-transferase (GST) is one of the detoxification enzyme systems and plays important role in inactivating endogenous and exogenous toxic products under oxidative stress. GSTM1/T1 polymorphisms are the most common polymorphisms of GST enzymes, and they have been associated with many diseases, such as rheumatoid arthritis, age-related macular degeneration, oral leukoplakia, prostate cancer, lung cancer, and cervical neoplasia [8,9,10,11,12,13]

Methods

Results

Conclusion