Objectives Coronary heart disease (CHD) susceptibility may be modulated partly through polymorphyisms in oxidative enzymes, one of wich is myeloperoxidase (MPO). Previous studies have evaluated the association between MPO-463 G/A, MPO-129 G/A gene polymorphism and the risk of CHD, but the results of those studies were inconsistent. This mate-analysis was conducted to assess the association between MPO-463 G/A, MPO-129 G/A gene polymorphism and CAD and evaluated the association in different ethnicities.

Methods Several electronic databases, such as : PUBMED, Science Citation Index and WANGFANG databases, were be used to search relevant articles up to Junaury 2013 by the keywords ((MPO OR Myeloperoxidase) AND (genetic polymorphism OR gene OR polymorphism) AND (coronary heart disease OR CHD)). A mate- analysis was performed by stata11.0 software to estimate the pooled odds ratio (OR) and the 95%confidence interval (CI). We also assessed heterogeneity and evaluate variations. Different effect models were used according to the difference in heterogeneity. Sensitivity analysis was assessed by omitting one study at a time. Publication bias was examined using Begg’s funnel plot and Egger’s linear regression test.

Results Finally, a total of 17 studies on MPO-463 G/A and MPO-129 G/A gene polymorphisms with CHD risk were included in this meta-analysis. Heterogeneity among studies was tested and sensitivity analysis was applied. For MPO-463 G/A polymorphism, 15 studies including 3449 cases and 3082 controls were combined to be analysised. The pooled OR for distribution frequency of A allele was 0.58 [95%CI (0.47-0.72)] and the pooled OR of genotypes (AA + AG) was 0.58,[95%CI (0.46-0.72)] which mean MPO-463 G/A allele A was significant associated with CHD. The results of the subgroup analysis in Asia population is the same but in European population is 0.79, [95% CI (0.58-1.08)]. Three of the 17 studies describe the risk between MPO-463 G/A and subgroup of stable angina pectoris in CHD, including 207 cases and 278 controls. Pooled OR of A allele and genotypes (AA + AG) for proven CHD were 0.45 [95%CI (0.15-1.37)] and 1.405, [95%CI (0.21-9.42)]. There are 3 studies involved 1535 CHD cases and 1655 controls investigated MPO-129 G/A gene showing that pooled OR for GG genotype is 0.86 [95% CI:0.64–1.17)].

Conclusions A allele of MPO-463 G/A polymorphism is significantly associated with a reduced risk of CHD but not in European population only. There was no evidence however, of a significant association between the MPO-129 G/A gene polymorphisms and CHD risk.