Abstract: Objective To investigate the relationship between matrix metalloproteinase-9 (MMP-9) gene polymorphism and genetic susceptibility to coronary heart disease. Methods A Meta-analysis on MMP-9 R279Q polymorphism and susceptibility to coronary heart disease was performed by searching for studies included in PubMed before January 1, 2012. For each study, odds ratios (ORs) and 95% confidence intervals (CIs) was calculated to assume homozygote comparison, dominant and recessive genetic models. Pooled ORs and 95% CIs was calculated and publication bias was assessed. All statistical analyses were conducted by STATA 11.0 software. Results A total of 5 case-control studies were analyzed in the study. The MMP-9 R279Q QQ genotype was not associated with the risk of coronary heart disease compared with R279Q RR genotype (QQ vs. RR: OR=0.866; 95%CI=0.713-1.052). Effect estimates from a dominant model [(QQ + RQ) vs. RR: OR= 0.909; 95%CI=0.809-1.020] or a recessive model [QQ vs. (RQ + RR):OR=0.902; 95%CI=0.750-1.086] suggest that the MMP-9 R279Q variants are not associated with coronary heart disease risk. Conclusion MMP-9 R279Q gene polymorphism may not be associated with genetic susceptibility to coronary heart disease.

Key words: MMP, Coronary heart disease, Gene polymorphism, Meta-analysis