Background: The plasminogen activator inhibitor-1 (PAI-1) promoter 4G/5G insertion/deletion polymorphism has been associated with increased risk of myocardial infarction (MI) and decreased risk of cerebrovascular events. Whether these results apply to young women is not known.
Methods: We genotyped 78 MI cases, 106 stroke cases and 385 age-matched controls from a population-based case-control study of MI and stroke in women < 45 years old.
Results: The risk of MI was significantly decreased in carriers of the 4G allele compared with 5G/5G homozygotes, and the association persisted upon adjustment for other risk factors (age- and race-adjusted OR 0.50, 95% CI 0.29-0.85). Carrying the 4G allele was not associated with stroke, either overall or according to subtype. The association of this polymorphism with MI or stroke did not vary significantly by presence or absence of established cardiovascular risk factors, assessed on either an additive or multiplicative scale.
Conclusions: These data suggest a decreased risk of MI among young women carrying the 4G allele of the PAI-1 4G/5G polymorphism. Although this result contrasts with those of previous studies of older adults and young men, it may highlight the influence of genetic factors on the development of MI within the context of particular hormonal or environmental influences.