Abstract 11339: Relationship of LPA Single Nucleotide Polymorphisms With Apolipoprotein (a) Isoforms and Biomarkers of Oxidized Lipoproteins in African-Americans, Caucasians and Hispanics: Results From the DALLAS Heart Study

Abstract

Background: Oxidized phospholipids (OxPL) measured on apolipoprotein B-100 particles (OxPL-apoB) are a measure of the pro-inflammatory activity of Lp(a). Lp(a) in plasma is genetically determined by variability in kringle IV (KIV) repeats and single nucleotide polymorphisms (SNPs) in the LPA gene, is causally related to cardiovascular disease (CVD) and has become a target of therapy. Methods and Results: OxPL-apoB IgG and IgM autoantibodies to oxidized LDL and apoB-immune complexes, KIV repeats of the major apolipoprotein (a) isoform, LPA snps rs3798220, rs10455872 and rs9457951 were measured in 3454 subjects (1798 African-Americans, 1032 Caucasian and 576 Hispanic) subjects enrolled in the Dallas Heart Study (Table). All 3 snps were highly correlated with the number of KIV repeats in African-Americans but only rs3798220 and rs10455872 were correlated with KIV repeats in Caucasians or Hispanics. rs3798220 and rs10455872 demonstrated strong correlations with Lp(a) and OxPL-apoB levels in subjects with low numbers of KIV repeats, whereas rs9457951 showed similar associations only in African-Americans. None of the LPA snps correlated with the other biomarkers of oxidation. Conclusion: Significant racial differences exist among LPA SNPs and their relationship to Lp(a), apolipoprotein (a) isoforms and OxPL-apoB. These findings may provide insights into the clinical variability of Lp(a)-mediated risk in different racial groups and suggests novel avenues of investigation and therapeutic potential in mitigating the CVD risk of Lp(a) and OxPL-apoB.