Significant associations between lipoprotein(a) and corrected apolipoprotein B-100 levels in African-Americans

Atherosclerosis. 2014 Jul;235(1):223-9. doi: 10.1016/j.atherosclerosis.2014.04.035. Epub 2014 May 10.

Abstract

Objectives: Lipoprotein(a), Lp(a), represents an apolipoprotein (apo) B-carrying lipoprotein, yet the relationship between Lp(a) and apoB levels has not been fully explored.

Methods: We addressed the relationship between Lp(a) and apoB-containing lipoprotein levels in 336 Caucasians and 224 African-Americans. Our approach takes unique molecular properties of Lp(a) as well as contribution of Lp(a) to the levels of these lipoproteins into account.

Results: Levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), apoB and apoB/apoA-1 did not differ across ethnicity. African-Americans had higher levels of Lp(a) and high-density lipoprotein cholesterol and lower triglyceride levels compared to Caucasians. Lp(a) levels were correlated with levels of TC (p < 0.005), LDL-C (p < 0.001), apoB (p < 0.05) or apoB/apoA-1 (p < 0.05) in both ethnic groups. These associations remained significant only in African-Americans after adjustments for the contribution of Lp(a)-cholesterol or Lp(a)-apoB. Furthermore, taking Lp(a)-apoB into account, allele-specific apo(a) levels were significantly associated with apoB levels and the apoB/apoA-1 ratio in African-Americans. The latter associations in African-Americans remained significant for allele-specific apo(a) levels for smaller apo(a) sizes (<26 K4 repeats), after controlling for the effects of age, sex, and BMI.

Conclusions: Although TC, LDL-C, and apoB levels were comparable between African-Americans and Caucasians, the associations of these parameters with Lp(a) and allele specific apo(a) levels differed between these two ethnic groups. In African-Americans, apoB and apoB/apoA-1 remained consistently and positively associated with both Lp(a) and allele-specific apo(a) levels after adjustments for the contribution of Lp(a)-apoB. The findings suggest an interethnic difference with a closer relationship between Lp(a) and apoB among African-Americans.

Keywords: Apo(a) sizes; Corrections for the contribution of Lp(a); Ethnicity; K4 repeats; Plasma lipids.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alleles
  • Apolipoprotein B-100 / blood*
  • Apolipoprotein B-100 / genetics
  • Atherosclerosis / blood
  • Atherosclerosis / ethnology*
  • Atherosclerosis / genetics
  • Black or African American / genetics*
  • Cholesterol / blood
  • Cholesterol, LDL / blood
  • Female
  • Humans
  • Lipoprotein(a) / blood*
  • Lipoprotein(a) / genetics
  • Male
  • Middle Aged
  • Protein Isoforms
  • Risk Assessment
  • Risk Factors
  • White People

Substances

  • Apolipoprotein B-100
  • Cholesterol, LDL
  • Lipoprotein(a)
  • Protein Isoforms
  • Cholesterol