Objective: The aim of this study is to investigate the potential role of functional myeloperoxidase (MPO) promoter polymorphisms in the occurrence of myocardial infarction (MI) in the Stockholm Heart Epidemiology Program.
Methods and results: Two MPO promoter polymorphisms, -129G/A and -463G/A, were genotyped in the Stockholm Heart Epidemiology Program population (n = 2774). The -129A allele was associated with a lower risk of MI in women [odds ratio (OR) (95% confidence interval): 0.65 (0.43-0.98), P = 0.03] but not in men [OR: 1.12 (0.86-1.47), P = 0.38]. When women were stratified by age and hormone replacement therapy, the protective effect of the -129A allele was only evident in women younger than 55 years or not receiving hormone replacement therapy. In these two groups, OR (95% confidence interval) for carriers of the -129A allele were 0.34 (0.12-0.92) (P = 0.03) and 0.51 (0.32-0.81) (P = 0.004), respectively. For the -463G/A polymorphism, no associations to MI risk were observed either in women or in men.
Conclusion: The A allele of the MPO -129G/A promoter polymorphism is associated with a reduced MI risk in women.