Objective: This study investigated whether the single nucleotide polymorphism (SNP) in the matrix metalloproteinase-9 (MMP-9) promoter (-1562C>T) is a significant risk factor for an acute myocardial infarction (AMI) and if SNPs affect the transcription of the gene that elevates the MMP-9 expression level.
Methods: A polymerase chain reaction, followed by a restriction fragment length polymorphism analysis, was performed in 173 control participants and 206 AMI patients. The serum levels of MMP-9 in the groups with or without the SNP were measured using ELISA and compared.
Results: There was a significantly higher incidence of th-1562C>T MMP-9 polymorphism in the AMI patients compared to the control group (27.6% vs 17.9%, p=0.04). A multiple logistic regression analysis of the risk factors for coronary artery disease and the MMP-9 polymorphism showed the MMP-9 polymorphism to be an important factor in the prediction of an AMI (odds ratio 1.67, 95% confidence interval 1.02-2.67, p=0.04). The serum level of MMP-9 was also higher in the group with the SNP than in the group without (494.8+/-3.66 ng/ml vs 309.5+/-2.19 ng/ml, p=0.04).
Conclusion: These results suggest that the -1562C>T polymorphism in the MMP-9 promoter is strongly associated with an AMI.