Platelet Glycoprotein IIIa PlA1/PlA2 Polymorphism Modulates the Risk of Myocardial Infarction in Non-Diabetics.

BACKGROUND: Genetic polymorphisms of platelet glycoprotein IIIa ( GPIIIa gene) have been investigated intensively in several thrombotic diseases, but their role in cardiovascular diseases remains controversial. This study aimed to investigate the association between platelet glycoprotein IIIa PlA1/PlA2 polymorphism and susceptibility to myocardial infarction in non-diabetics.

METHODS: A total of 200 participants were recruited for the study, 100 non-diabetic patients with myocardial infarction and 100 apparently healthy volunteers as a control group. GPIIIa PlA1/PlA2 polymorphism was analyzed by polymerase chain reaction-restriction fragment length polymorphism.

RESULTS: The distribution of GPIIIa PlA1/PlA2 polymorphic genotypes among the study groups was significantly different (P value = 0.00). The PlA1/PlA2 and PlA2/PlA2 genotypes were more frequent in the patients with myocardial infarction while the genotype PlA1/PlA1 was more prevalent in the control group. There was a statistically significant association between the PlA1/PlA1 genotype and reduced risk of both ST-segment elevation myocardial infarction (odds ratio (OR) = 0.19; 95% confidence interval (CI): 0.09 - 0.34, P value = 0.00) and non-ST-segment elevation myocardial infarction (OR = 0.21; 95% CI: 0.09 - 0.45, P value = 0.00). The genotype PlA1/PlA2 was found to be associated with an increased risk of both types of myocardial infarction (OR = 6.0; 95% CI: 2.61 - 13.8, P value = 0.00 for ST-segment elevation myocardial infarction and OR = 6.65; 95% CI: 2.69 - 16.45, P value = 0.00 for non- ST-segment elevation myocardial infarction. In the patients carrying the PlA1/PlA2 genotype, the risk of ST-segment elevation myocardial infarction was increased to about 14 folds in the presence of family history (OR: 13.57, 95% CI: 1.42 - 130.03, P value = 0.02), and the risk of non-ST-segment elevation myocardial infarction increased to about 18 folds in the smokers carrying the genotype PlA2/PlA2 (OR: 17.63, 95% CI: 0.96 - 324.70, P value = 0.05).

CONCLUSIONS: The GPIII PlA1/PlA1 genotype is associated with a reduced risk of ST-segment elevation and non-ST-segment elevation myocardial infarction, while PlA1/PlA2 is associated with an increased risk of both types of myocardial infarction.