title: Association of Lp-PLA(2) activity with allele-specific Lp(a) levels in a bi-ethnic population.
abstract: OBJECTIVE
  Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) and lipoprotein(a) [Lp(a)] have been implicated as cardiovascular disease risk factors, and are differentially regulated across ethnicity. We investigated the association between Lp-PLA(2) activity and allele-specific apolipoprotein(a) [apo(a)] levels in a bi-ethnic population.
  
  
  METHODS
  Lp-PLA(2) activity, Lp(a) and allele-specific apo(a) levels were determined in 224 African Americans and 336 Caucasians.
  
  
  RESULTS
  Lp-PLA(2) activity level was higher among Caucasians compared to African Americans (173 + or - 41 nmol/min/ml vs. 141 + or - 39 nmol/min/ml, P<0.001), and positively associated with Lp(a), total and LDL cholesterol, triglyceride, apolipoprotein B-100, and negatively with HDL cholesterol levels in both ethnic groups. The association between Lp-PLA(2) activity and Lp(a) was stronger among African Americans compared to Caucasians (R=0.238, beta(1)=3.48, vs. R=0.111, beta(1)=1.93, respectively). The Lp-PLA(2) activity level was significantly associated with allele-specific apo(a) levels for smaller (<26 K4 repeats) apo(a) sizes in both ethnic groups (P=0.015 for African Americans, P=0.038 for Caucasians). In contrast, for larger (>26 K4 repeats) apo(a) sizes, high Lp-PLA(2) activity levels were associated with higher allele-specific apo(a) levels in African Americans (P=0.009), but not in Caucasians.
  
  
  CONCLUSIONS
  The association between Lp-PLA(2) activity and allele-specific apo(a) levels differs across African American-Caucasian ethnicity.
authors.affiliation: Department of Medicine, University of California, Davis, CA, USA.
authors.forename: Byambaa
authors.initials: B
authors.lastname: Enkhmaa
authors.forename: Erdembileg
authors.initials: E
authors.lastname: Anuurad
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Pearson
authors.forename: Lars
authors.initials: L
authors.lastname: Berglund
mesh_terms: D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000096:biosynthesis / Q000235:genetics*; D001741:Black or African American; D000368:Aged; D000483:Alleles; D053299:Apolipoprotein B-100 / Q000097:blood; D044383:Black People; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D005006:Ethnicity; D005260:Female; D006801:Humans; D017270:Lipoprotein(a) / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D014280:Triglycerides / Q000097:blood; D044465:White People
chemical_list: D053299:Apolipoprotein B-100; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D017270:Lipoprotein(a); D014280:Triglycerides; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase
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