Relationships between genetic polymorphisms of E670G in PCSK9 gene and coronary artery disease: a meta-analysis

Objective: Proprotein convertase subtilisin-like kexin type 9 (PCSK9) gene E670G Polymorphism has been reported to be associated with coronary artery disease (CAD) and risk factors. However, the results remain controversial. We sought to perform a meta-analysis to investigate the relationships between genetic polymorphisms of E670G in PCSK9 gene and the risk of CAD. Methods: Literature searches were performed to identify all published relevant case-control studies without any language restrictions. Meta-analysis was conducted using the Review Manager software (version 5.2). Heterogeneity was investigated and measured using Cochran's Q-statistic and the inconsistency index (I-2) test; Crude odds ratios (OR) with their corresponding 95% confidence interval (CI) were calculated. Results: A total of 5 case-control studies among 871 patients with CAD and 1144 control subjects were included in the meta-analysis. we found a correlation between PCSK9 genetic polymorphisms and increased risk for CAD under all of the genetic model (allele model: OR: 1.56, 95% CI: 1.21-2.01, P < 0.001; dominant model: OR: 1.46, 95% CI: 1.14-1.88, P = 0.003; recessive model: OR: 3.46, 95% CI: 1.19-10.10, P = 0.02; homozygous model: OR: 3.89, 95% CI: 1.35-11.20, P = 0.01; Heterozygous model: OR: 1.43, 95% CI: 1.08-1.92, P = 0.01; respectively). Conclusion: The results of the meta-analysis indicated that genetic polymorphism of E670G in PCSK9 gene might be involved in pathogenesis of CAD; the 670G carriers may be closely related to the risk of CAD.