title: African American race but not genome-wide ancestry is negatively associated with atrial fibrillation among postmenopausal women in the Women's Health Initiative.
abstract: BACKGROUND
  Atrial fibrillation (AF) is the most common arrhythmia in women and is associated with higher rates of stroke and death. Rates of AF are lower in African American subjects compared with European Americans, suggesting European ancestry could contribute to AF risk.
  
  
  METHODS
  The Women's Health Initiative (WHI) Observational Study (OS) followed up 93,676 women since the mid 1990s for various cardiovascular outcomes including AF. Multivariate Cox hazard regression analysis was used to measure the association between African American race and incident AF. A total of 8,119 African American women from the WHI randomized clinical trials and OS were genotyped on the Affymetrix Human SNP Array 6.0. Genome-wide ancestry and previously reported single nucleotide polymorphisms associated with AF in European cohorts were tested for association with AF using multivariate logistic regression analyses.
  
  
  RESULTS
  Self-reported African American race was associated with lower rates of AF (hazard ratio 0.43, 95% CI 0.32-0.60) in the OS, independent of demographic and clinical risk factors. In the genotyped cohort, there were 558 women with AF. By contrast, genome-wide European ancestry was not associated with AF. None of the single nucleotide polymorphisms previously associated with AF in European populations, including rs2200733, were associated with AF in the WHI African American cohort.
  
  
  CONCLUSIONS
  African American race is significantly and inversely correlated with AF in postmenopausal women. The etiology of this association remains unclear and may be related to unidentified environmental differences. Larger studies are necessary to identify genetic determinants of AF in African Americans.
authors.affiliation: Division of Cardiovascular Medicine, Department of Medicine, Stanford University School of Medicine, Stanford, CA. Electronic address: mvperez@stanford.edu.
authors.forename: Marco V
authors.initials: MV
authors.lastname: Perez
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Hoffmann
authors.forename: Hua
authors.initials: H
authors.lastname: Tang
authors.forename: Timothy
authors.initials: T
authors.lastname: Thornton
authors.forename: Marcia L
authors.initials: ML
authors.lastname: Stefanick
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Larson
authors.forename: Charles
authors.initials: C
authors.lastname: Kooperberg
authors.forename: Alex P
authors.initials: AP
authors.lastname: Reiner
authors.forename: Bette
authors.initials: B
authors.lastname: Caan
authors.forename: Carlos
authors.initials: C
authors.lastname: Iribarren
authors.forename: Neil
authors.initials: N
authors.lastname: Risch
mesh_terms: D001741:Black or African American / Q000235:genetics*; D000368:Aged; D001281:Atrial Fibrillation / Q000208:ethnology* / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D055106:Genome-Wide Association Study; D005838:Genotype; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008875:Middle Aged; D015999:Multivariate Analysis; D020641:Polymorphism, Single Nucleotide; D017698:Postmenopause / Q000208:ethnology*; D016016:Proportional Hazards Models; D044469:Racial Groups; D018570:Risk Assessment; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D044465:White People / Q000235:genetics*; D016387:Women's Health