The M235T polymorphism in the angiotensinogen gene and atrial fibrillation: A meta-analysis

Objective: The M235T polymorphism in the angiotensinogen gene has been reported to be associated with the development of atrial fibrillation (AF).However, results from observational studies are conflicting. Methods: PubMed, google scholar and China National Knowledge Infrastructure database(2000.1-2013.4) were searched for eligible articles; four separate studies with 2580 subjects on the relationship between M235T polymorphism and AF were analyzed by meta-analysis. The associations between M235T polymorphism and AF risk were estimated by pooled odds ratio (OR) and 95% confidence interval (CI) using a fixed or random-effects model. Results: There was a significant association between M235T polymorphism and AF. The pooled OR for the recessive model in the total population was 2.17 (95% CI: 1.39-3.38, I-2=0%). In a subgroup analysis by nationality, the pooled OR for TT vs. MM genotype was 0.55 (95% CI: 0.32-0.95, I-2=0%) and the pooled OR for the recessive model was 1.86 (95% CI: 1.08-3.20, I-2=0%) in Asians. Conclusions: The current meta-analysis suggested that the M235T polymorphism in the angiotensinogen gene might be related to the increased risk of AF in Asians. Conclusive evidence on the effects of the variants in AF should be addressed in further studies.