Impact of<i>CYP1A1</i>Polymorphisms on Susceptibility to Chronic Obstructive Pulmonary Disease: A Meta-Analysis
Several studies have evaluated the association between CYP1A1 polymorphisms and the susceptibility of chronic obstructive pulmonary disease (COPD) with inconclusive results. We performed the first comprehensive meta-analysis to summarize the association between CYP1A1 polymorphisms and COPD risk.A systematic literature search was conducted (up to April 2015) in five online databases: PubMed, EMBASE, China National Knowledge Infrastructure (CNKI), WeiPu, and WanFang databases. The strength of association was calculated by odds ratio (OR) and corresponding 95% confidence interval (CI).Seven case-control studies with 1050 cases and 1202 controls were included. Our study suggested a significant association between the MspI polymorphism and COPD risk (CC versus TC + TT: OR = 1.57, CI: 1.09-2.26, P = 0.02; CC versus TT: OR = 1.73, CI: 1.18-2.55, P = 0.005). For the Ile/Val polymorphism, a significant association with COPD risk was observed (GG versus AG + AA: OR = 2.75, CI: 1.29-5.84, P = 0.009; GG versus AA: OR = 3.23, CI: 1.50-6.93, P = 0.003; AG versus AA: OR = 1.39, CI: 1.01-1.90, P = 0.04). Subgroup analysis indicated a significant association between the MspI variation and COPD risk among Asians (CC versus TC + TT: OR = 1.70, CI: 1.06-2.71, P = 0.03; CC versus TT: OR = 1.84, CI: 1.11-3.06, P = 0.02).The MspI and Ile/Val polymorphisms might alter the susceptibility of COPD, and MspI polymorphism might play a role in COPD risk among Asian population.