title: Genetic admixture is associated with plasma hemostatic factor levels in self-identified African Americans and Hispanics: the Multi-Ethnic Study of Atherosclerosis.
abstract: BACKGROUND
  Epidemiologic studies report that self-identified African Americans typically have higher hemostatic factor levels than do self-identified Caucasians or Hispanics.
  
  
  OBJECTIVE
  To enhance understanding of phenotypic variation in hemostatic factor levels by race/ethnicity, we evaluated the relationship between genetic ancestry and hemostatic factor levels among Multi-Ethnic Study of Atherosclerosis (MESA) study participants.
  
  
  METHODS
  Our sample included 712 African American and 701 Hispanic men and women aged 45 to 84 years. Individual global ancestry was estimated from 199 genetic markers using STRUCTURE. Linear regression models were used to evaluate the relationship between ancestry and hemostatic factor levels, adjusting for age, gender, education, income and study site.
  
  
  RESULTS
  Among African Americans, mean ± standard deviation (SD) ancestry was estimated as 79.9% ± 15.9% African and 20.1% ± 15.9% European. Each SD (16%) greater African ancestry was associated with 2.1% higher fibrinogen levels (P = 0.007) and 3.5% higher plasmin-antiplasmin (PAP) levels (P = 0.02). Ancestry among African Americans was not related to levels of factor (F)VIII or D-dimer. Mean ± SD estimated ancestry among Hispanics was 48.3% ± 23.8% Native American, 38.8% ± 21.9% European, and 13.0% ± 8.9% African. In Hispanics, each SD (19%) greater African ancestry was associated with 2.7% higher fibrinogen levels (P = 0.009) and 7.9% higher FVIII levels (P = 0.0002). In Hispanics, there was no relation between African ancestry and D-dimer or PAP levels, or between European ancestry and hemostatic factor levels.
  
  
  CONCLUSIONS
  Greater African ancestry among African Americans and Hispanics was associated with higher levels of several hemostatic factors, notably fibrinogen. These results suggest that genetic heterogeneity contributes, albeit modestly, to racial/ethnic differences in hemostatic factor levels.
authors.affiliation: Division of Epidemiology & Community Health, University of Minnesota, Minneapolis, MN 55454, USA. lutsey@umn.edu
authors.forename: P L
authors.initials: PL
authors.lastname: Lutsey
authors.forename: C L
authors.initials: CL
authors.lastname: Wassel
authors.forename: M
authors.initials: M
authors.lastname: Cushman
authors.forename: M M
authors.initials: MM
authors.lastname: Sale
authors.forename: J
authors.initials: J
authors.lastname: Divers
authors.forename: A R
authors.initials: AR
authors.lastname: Folsom
mesh_terms: D001741:Black or African American / Q000235:genetics*; D000368:Aged; D000369:Aged, 80 and over; D050197:Atherosclerosis / Q000097:blood / Q000208:ethnology* / Q000235:genetics*; D015415:Biomarkers / Q000097:blood; D005169:Factor VIII / Q000032:analysis / Q000235:genetics; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis; D005340:Fibrinogen / Q000032:analysis; D005341:Fibrinolysin / Q000032:analysis; D014644:Genetic Variation; D005838:Genotype; D006487:Hemostasis / Q000235:genetics*; D006630:Hispanic or Latino / Q000235:genetics*; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D010641:Phenotype; D011446:Prospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D000979:alpha-2-Antiplasmin / Q000032:analysis
chemical_list: D015415:Biomarkers; C047687:Factor VIII Leiden; D005338:Fibrin Fibrinogen Degradation Products; D000979:alpha-2-Antiplasmin; C036309:fibrin fragment D; C037742:plasmin-plasmin inhibitor complex; D005169:Factor VIII; D005340:Fibrinogen; D005341:Fibrinolysin