Association between myeloperoxidase polymorphisms and its plasma levels with severity of coronary artery disease.

Abstract Objectives Myeloperoxidase (MPO) polymorphism −463 has been related to higher cardiovascular risk. This study was conducted to test whether the MPO promoter polymorphism −463A/G and MPO plasma levels are associated with coronary artery disease (CAD) severity. Design and methods Patients submitted to elective coronariography were enrolled, CAD severity was assessed and blood samples collected to identify the MPO polymorphism and its plasma levels. Results Genotypes were determined in 118 patients. Among these patients, 12 (10%) were homozygous for AA, 69 (58%) for GG and 37 (32%) were heterozygous. Mean MPO plasma levels were 8.6 ± 4.7 ng/mL for AA, 8.6 ± 7.0 ng/mL for AG and 9.4 ± 5.6 ng/mL for GG genotypes. The CAD severity was not associated with MPO genotypes ( p  = 0.43), however, patients with higher CAD score presented higher MPO levels ( p  = 0.02). Conclusion We found no association between MPO polymorphism and CAD severity, although a relation was observed for MPO plasma levels and extension of CAD.