title: Long-Term Hormone Replacement Therapy Is Associated with Low Coronary Artery Calcium Levels in a Cohort of Older Women: The Age, Gene/Environment Susceptibility-Reykjavik Study.
abstract: To assess the relationship between hormone replacement therapy (HRT) and coronary artery calcium (CAC).
  
  
  
  Cross-sectional.
  
  
  
  Established population-based cohort in Reykjavik, Iceland.
  
  
  
  Women (mean age 76 ± 5) who had completed questionnaires on HRT use (N = 2,867).
  
  
  
  Coronary artery calcium assessed using computed tomography was the outcome variable and was compared between women with history of HRT and those who had never used HRT and analyzed according to age, length of use, and time after menopause that HRT was initiated.
  
  
  
  Eight hundred seventy-two (30.4%) participants had used HRT, and 312 (10.9%) were current users. After adjustment for age, other late-life variables, and a propensity score based on midlife data for HRT use as observed in late life, there were significant negative associations between CAC and history and length of HRT use. This association was evident in all age categories. When HRT had been used for longer than 15 years, median CAC level was less than 50% of that observed in never users. The lowest CAC was observed in those who started HRT within 5 years after menopause. The prevalence of coronary events was comparable in both groups.
  
  
  
  A strong association was found between long-term HRT use and low CAC. The negative association between duration of HRT and CAC was evident in all age groups of older women.
authors.affiliation: Landspitali University Hospital, Reykjavik, Iceland.|University of Iceland, Reykjavik, Iceland.
authors.forename: Adalsteinn
authors.initials: A
authors.lastname: Gudmundsson
authors.affiliation: University of Iceland, Reykjavik, Iceland.|Icelandic Heart Association, Kopavogur, Iceland.
authors.forename: Thor
authors.initials: T
authors.lastname: Aspelund
authors.affiliation: Landspitali University Hospital, Reykjavik, Iceland.|University of Iceland, Reykjavik, Iceland.|Icelandic Heart Association, Kopavogur, Iceland.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Sigurdsson
authors.affiliation: Intramural Research Program, National Institute on Aging, Bethesda, Maryland.
authors.forename: Tamara
authors.initials: T
authors.lastname: Harris
authors.affiliation: Intramural Research Program, National Institute on Aging, Bethesda, Maryland.
authors.forename: Lenore J
authors.initials: LJ
authors.lastname: Launer
authors.affiliation: University of Iceland, Reykjavik, Iceland.|Icelandic Heart Association, Kopavogur, Iceland.
authors.forename: Vilmundur
authors.initials: V
authors.lastname: Gudnason
authors.affiliation: Landspitali University Hospital, Reykjavik, Iceland.|University of Iceland, Reykjavik, Iceland.
authors.forename: Helgi
authors.initials: H
authors.lastname: Jonsson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000072226:Computed Tomography Angiography; D017023:Coronary Angiography; D003430:Cross-Sectional Studies; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D057216:Propensity Score; D061205:Vascular Calcification / Q000000981:diagnostic imaging / Q000453:epidemiology*
keywords: coronary artery calcium; epidemiology; hormone replacement therapy; older women