Serum Concentration and Polymorphisms of Apolipoproteins A-I and B, and Risk of Coronary Artery Disease

Abstract

Introduction: Variations in the apoprotein apoA-I and apoB genes have been associated with their serum concentration, and thus with Coronary Artery Disease (CAD). This study determined the relationship between polymorphism and the serum concentration of apoA-I and apoB in a group of patients with angiographically documented CAD.

Materials and methods: Polymorphic sites, XbaI (in apoB), and MspI (in apo A-I) and serum concentrations in these lipoproteins were determined in a population of 231patients classified into two groups: patients with significant CAD (coronary obstruction ≥50%) and patients with mild CAD (coronary obstruction <50%); the apoB/apoA-I ratio was then calculated.

Results: It was found that the M2 allele in the apoA-I acts as a risk factor for coronary artery disease, odds ratio=1.78(confidence interval: 1.21 – 2.61), p =0.002. Nosignificant differences were found between the apoA-I concentration values and the corresponding MspI polymorphism genotypes in the two study groups. Meanwhile, the apoB concentration presented significant differences among the XbaI (p=0.027) polymorphism genotypes, with greater values for the heterozygous genotype in patients with CAD≥50%. Likewise, a significantly abnormal difference was evident in the apoB/apoA-I ratio among the two groups, with a greater value for patients with mild CAD.

Conclusion: the data showed that the M2allele may be a risk factor for CAD in this population. Additionally, it showed that there is a relationship between apoB serum concentration and XbaI polymorphism; relationship which manifests itself more strongly in patients with CAD. There was no relationship established between the MspI polymorphism of apoA-I and its serum concentration. Other studies are necessary in order to establish the anomalous behavior of the apoB/apoA-I relation in this population.