Lp(a) impairs blood vessel function most strongly in African Americans, who have nearly 4 times higher levels than Caucasians, a multiethnic study of 89 people (J Am Coll Cardiol 2004)

Original title: High lipoprotein(a) levels and small apolipoprotein(a) sizes are associated with endothelial dysfunction in a multiethnic cohort

J Am Coll Cardiol · 19 May 2004 · 7

Wu HD, Berglund L, Dimayuga C, Jones J, Sciacca RR, Di Tullio MR, Homma S

This study examined Lp(a) and apolipoprotein(a) isoform size in relation to endothelial function in a multiethnic cohort of 89 healthy subjects (age 42, 50 men, 39 women) free of other cardiac risk factors, measuring flow-mediated dilation (FMD) and nitrate-induced dilation of the brachial artery. Plasma Lp(a) was lowest in Caucasians (18.3 mg/dL, n=40), intermediate in Hispanics (30.2 mg/dL, n=21), and highest in African Americans (68.8 mg/dL, n=28). Lp(a) correlated inversely with FMD (r=-0.33, P<0.005), remaining significant after adjusting for sex (P=0.002), but not with nitrate-induced dilation (r=0.06, P=0.60). Subjects with small apo(a) size (22 kringle-4 repeats or fewer) had significantly lower FMD than those with larger apo(a) (2.23% vs 6.26%, P<0.0001), regardless of Lp(a) level. The findings support an independent role for Lp(a) in atherogenesis, most evident in African Americans, partly attributable to its apo(a) component.

Original abstract

Objectives: This study sought to determine the effect of lipoprotein(a), or Lp(a), levels and apolipoprotein(a), or apo(a), sizes on endothelial function and to explore ethnic differences in their effects.

Background: Although high levels of Lp(a) have been shown to confer increased cardiovascular risk in Caucasians, its significance in non-Caucasian populations is uncertain. The pathogenic role of the apo(a) component of Lp(a) is also unclear.

Methods: The relationship of Lp(a) levels and apo(a) sizes to endothelial function was examined in a multiethnic cohort of 89 healthy subjects (age 42 +/- 9 years; 50 men, 39 women) free of other cardiac risk factors. Endothelium-dependent, flow-mediated dilation (FMD) and endothelium-independent, nitrate-induced dilation (NTG) were assessed by ultrasound imaging of the brachial artery.

Results: Plasma Lp(a) levels were lowest in Caucasians (18.3 +/- 21.1 mg/dl, n = 40); intermediate in Hispanics (30.2 +/- 30.5 mg/dl, n = 21); and highest in African Americans (68.8 +/- 46.0 mg/dl, n = 28). Lipoprotein(a) levels were found to correlate inversely to FMD (r = -0.33, p < 0.005) but not to NTG (r = 0.06, p = 0.60). This association remained significant after adjusting for gender (p = 0.002). In addition, subjects with small apo(a) size of <or=22 kringle 4 repeats had significantly lower FMD than those with large apo(a) (2.23 +/- 2.37% vs. 6.26 +/- 4.29%, p < 0.0001), irrespective of Lp(a) levels.

Conclusions: These findings support an independent role of Lp(a) in atherogenesis, an effect that is particularly evident in African Americans. The proatherogenic property of Lp(a) can be attributed in part to its apo(a) component.

Summary written by lp-a.org from the published abstract; figures as published. Page updated 18 August 2026. Methods.