Meta- and pooled analyses of the effect of glutathione S-transferase M1 and T1 deficiency on chronic obstructive pulmonary disease

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a complex polygenic disease in which gene-environment interactions are very important. A number of studies have investigated the genotypes of glutathione S-transferase M1 and T1 (GSTM1 and GSTT1) in relation to COPD susceptibility in different populations. However, the results of individual studies have been inconsistent.

METHODS: To address the inconsistent findings in studies of the association of the polymorphism of the GSTM1 and GSTT1 genes with susceptibility to COPD, we performed a meta-analysis of the published data. We searched the Medline database for case-control studies published from 1966 to July 2008. Data were extracted and pooled, and ORs were calculated with their 95%CIs.

RESULTS: Twelve eligible studies comprising 1697 patients with COPD and 1867 controls were included in the meta-analysis. The pooled result showed that the GSTM1 deficiency was associated with risk of COPD (OR 1.46, 95%CI 1.16–1.83). Subgroup analysis supported the results in smoking and non-Asian populations, but not in Asian populations. The GSTT1 deficiency was not associated with risk of COPD.

CONCLUSIONS: The GSTM1 gene is a genetic contributor to overall COPD susceptibility in non-Asian populations, and the GSTT1 gene is not associated with COPD.