title: Prospective study of γ' fibrinogen and incident venous thromboembolism: The Longitudinal Investigation of Thromboembolism Etiology (LITE).
abstract: BACKGROUND
  Epidemiological studies generally have not found plasma total fibrinogen to be a risk factor for venous thromboembolism (VTE), but several have reported associations between variants in the fibrinogen gamma gene (FGG) and VTE. A case-control study in whites suggested plasma γ' fibrinogen concentration may be associated inversely with VTE, but this was not replicated in African Americans.
  
  
  OBJECTIVE
  To examine the prospective association between γ' fibrinogen concentrations and occurrence of VTE.
  
  
  METHODS
  We used the Longitudinal Investigation of Thromboembolism Etiology (LITE), involving two pooled population-based cohorts in the United States including 16,234 participants. The cohorts comprised white and African American men and women, aged 50years and older at study onset in the early 1990s. We identified VTEs during follow-up and documented they met standardized diagnostic criteria.
  
  
  RESULTS
  During two decades of follow-up, neither γ' fibrinogen nor total fibrinogen nor their ratio was associated with VTE overall (n=521 VTEs), in subgroups defined by race, or in other subgroups. In both race groups, the minor allele of FGG rs2066865 was associated with lower γ' fibrinogen concentrations, but this allele was not associated with VTE.
  
  
  CONCLUSIONS
  A lower plasma concentration of γ' fibrinogen in healthy adults does not appear to increase VTE risk.
authors.affiliation: Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis, MN 55454, United States. Electronic address: folso001@umn.edu.
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Folsom
authors.affiliation: Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis, MN 55454, United States.
authors.forename: Weihong
authors.initials: W
authors.lastname: Tang
authors.affiliation: Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis, MN 55454, United States.
authors.forename: Kristen M
authors.initials: KM
authors.lastname: George
authors.affiliation: Department of Epidemiology, University of Washington, Seattle, WA 98101, United States.
authors.forename: Susan R
authors.initials: SR
authors.lastname: Heckbert
authors.affiliation: Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis, MN 55454, United States.
authors.forename: Richard F
authors.initials: RF
authors.lastname: MacLehose
authors.affiliation: Department of Medicine, University of Vermont, Burlington, VT 55446, United States; Department of Pathology, University of Vermont, Burlington, VT 05446, United States.
authors.forename: Mary
authors.initials: M
authors.lastname: Cushman
authors.affiliation: Division of Epidemiology & Community Health, School of Public Health, University of Minnesota, Minneapolis, MN 55454, United States.
authors.forename: James S
authors.initials: JS
authors.lastname: Pankow
mesh_terms: D000368:Aged; D005260:Female; D005340:Fibrinogen / Q000032:analysis / Q000235:genetics*; D015241:Fibrinogens, Abnormal / Q000032:analysis / Q000235:genetics*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D011446:Prospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D054556:Venous Thromboembolism / Q000097:blood / Q000453:epidemiology* / Q000235:genetics*
chemical_list: D015241:Fibrinogens, Abnormal; C527521:fibrinogen gamma'; D005340:Fibrinogen
keywords: Fibrinogen; Fibrinogen gamma; Prospective study; Pulmonary embolus; Venous thrombosis