Association of Glutathione S-Transferase M1 null genotype with inflammatory bowel diseases: A systematic review and meta-analysis.

Abstract

Ulcerative colitis (UC) and Crohn disease (CD) are the 2 main types of inflammatory bowel diseases (IBDs). Several studies have been conducted to investigate the association of Glutathione S-Transferase M1 (GSTM1) null genotype with UC and CD, but the results are inconsistent. Here, we performed a meta-analysis to clarify this controversy based on relative large sample size. A systematic article searching was conducted in the PubMed, EMBASE, SCOPUS, WOS, ProQuest, Chinese National Knowledge Infrastructure (CNKI), and Chinese Wanfang databases up to August 31, 2019. Meta-analysis results were synthesized by using crude odds ratio (OR) with its 95% confidence interval (CI). Heterogeneity, sensitivity analysis, subgroup analysis, and publication bias were assessed by using STATA 11.0 software. A total of 15 relevant studies including 4353 IBDs patients (1848 CD cases, 2505 UC cases) and 5413 controls were included in this meta-analysis. Totally, we found a significant association between GSTM1 null genotype and risk to IBDs in the overall populations (OR = 1.37, 95%CI = 1.13-1.65, P = .001). Stratified by ethnicity, we found a significant association between GSTM1 null genotype and risk to IBDs in the Asian population (OR = 2.54, 95%CI = 2.15-3.00, P = .001), but not in the Caucasian population. Stratified by disease type, we found a significant association between GSTM1 null genotype with CD in the Asian population (OR = 2.37, 95%CI = 1.11-5.06, P = .026), and with UC in the Asian (OR = 2.48, 95%CI = 1.93-3.20, P = .001) population. In addition, funnel plot and Egger linear regression test suggests no publication bias in all genetic models. GSTM1 null genotype is associated with susceptibility to IBD, UC, and CD in the Asian population. Further well-designed studies are still needed to confirm these findings.