Relationship between gene polymorphism of the PAI-1 promoter and myocardial infarction

Objective To investigate the association between gene polymorphism of the p lasminogen activator inhibitor-1 (PAI-1) and myocardial infarction (MI) in Chinese. Methods PAI-1 genotyping with polymerase chain reaction-restriction fragmen t length polymorphism (PCR-RFLP) and allele specific polymerase chain react ion (ASPCR) was performed in 87 myocardial infarction patients and 92 unrel ated healthy controls. All subjects' clinical features and PAI-1 activity w ere tested. Results There were two polymorphisms within the promoter, a G/A single base substitution polymorphism upstream at -844 bp, and a single guanosine dele tion/insertion 4G/5G polymorphism -675 bp upstream from the start of transc ription. Significant differences between the patients and the controls were observed neither for the frequencies of the GG, GA and AA genotypes nor fo r the PAI-1 activities of these three types. But for the 4G/5G polymorphism , there were significant differences between patients and controls for the frequencies of the 4G/4G, 4G/5G and 5G/5G genotypes (P < 0.05). In the MI g roup, the PAI-1 activity of the 4G/4G type was significantly higher than th at of the 5G/5G type (P < 0.05). Further more, a positive correlation betwe en the glucose level and PAI-1 activity was found (r = 0.34, P = 0.02). Conclusion This study indicates that the 4G/5G gene polymorphism of PAI-1 i s associated with myocardial infarction, that 4G/4G type is probably an imp ortant hereditary risk factor, and that glucose has functional importance i n regulating PAI-1 activity.