High levels of inflammatory biomarkers are associated with increased allele-specific apolipoprotein(a) levels in African-Americans.

Abstract

BACKGROUND:

A role of inflammation for cardiovascular disease (CVD) is established. Lipoprotein(a) [Lp(a)] is an independent CVD risk factor where plasma levels are determined by the apolipoprotein(a) [apo(a)] gene, which contains inflammatory response elements.

DESIGN:

We investigated the effect of inflammation on allele-specific apo(a) levels in African-Americans and Caucasians. We determined Lp(a) levels, apo(a) sizes, allele-specific apo(a) levels, fibrinogen and C-reactive protein (CRP) levels in 167 African-Americans and 259 Caucasians.

RESULTS:

Lp(a) levels were increased among African-Americans with higher vs. lower levels of CRP [<3 vs. > or =3 mg/liter (143 vs. 108 nmol/liter), P = 0.009] or fibrinogen (<340 vs. > or =340 mg/liter, P = 0.002). We next analyzed allele-specific apo(a) levels for different apo(a) sizes. No differences in allele-specific apo(a) levels across CRP or fibrinogen groups were seen among African-Americans or Caucasians for small apo(a) sizes (<22 kringle 4 repeats). Allele-specific apo(a) levels for medium apo(a) sizes (22-30 kringle 4 repeats) were significantly higher among African-Americans, with high levels of CRP or fibrinogen compared with those with low levels (88 vs. 67 nmol/liter, P = 0.014, and 91 vs. 59 nmol/liter, P < 0.0001, respectively). No difference was found for Caucasians.

CONCLUSIONS:

Increased levels of CRP or fibrinogen are associated with higher allele-specific medium-sized apo(a) levels in African-Americans but not in Caucasians. These findings indicate that proinflammatory conditions result in a selective increase in medium-sized apo(a) levels in African-Americans and suggest that inflammation-associated events may contribute to the interethnic difference in Lp(a) levels between African-Americans and Caucasians.

• Authors: Erdembileg Anuurad, Jill Rubin, Alan Chiem, Russell P Tracy, Thomas A Pearson, Lars Berglund
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 93 Issue 4 Pg. 1482-8 (Apr 2008) ISSN: 0021-972X [Print] United States
• PMID: 18252779 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers
• Fibrinogen
• C-Reactive Protein
• Apoprotein(a)

Topics

• Black or African American (genetics)
• Alleles
• Apoprotein(a) (blood)
• Biomarkers
• C-Reactive Protein (analysis)
• Female
• Fibrinogen (analysis)
• Humans
• Inflammation (ethnology)
• Male
• White People