title: Hormone replacement therapy and heart disease: the remains of the oestrogen hypothesis.
abstract: BACKGROUND
  While observational data for postmenopausal women using hormone replacement therapy (HRT) have shown a protective effect against cardiovascular disease, prospective, randomised trials have demonstrated a harmful effect on the vascular system.
  
  
  RESULTS
  The effects of HRT on lipids, haemostatic parameters, inflammation, and the vascular wall are described. Reasons for the different results of observational and experimental studies of HRT are postulated. The timing of hormonal supplementation seems crucial. Used chronically, HRT has no harmful effects; however, first-time use of HRT after a recent cardiovascular event results in an early increase in adverse cardiovascular events. In most observational studies, women started HRT for postmenopausal symptoms, whereas in experimental studies women started HRT 10 to 20 years or longer after the menopause.
  
  
  CONCLUSIONS
  HRT has more effect in maintaining vascular health than in alleviating endothelial dysfunction. HRT is not beneficial but harmful in women at risk of a cardiovascular event. The interval between the menopause and starting HRT plays a crucial role in the effectiveness of HRT on the vascular system.
authors.forename: A H E M
authors.initials: AH
authors.lastname: Maas
authors.forename: Y T
authors.initials: YT
authors.lastname: van der Schouw
authors.forename: D E
authors.initials: DE
authors.lastname: Grobbee
authors.forename: Y
authors.initials: Y
authors.lastname: van der Graaf
keywords: cardiovascular disease; hormone replacement therapy; prevention