title: The effect of oestradiol implants on regional and total bone mass: a three-year longitudinal study.
abstract: OBJECTIVE
  Although there is evidence from cross-sectional studies that percutaneous oestrogen administration protects against menopausal bone loss, few longitudinal data are available. We have examined the effect of 3 years' treatment with percutaneous oestradiol on total body calcium, spinal trabecular bone mineral density and radial bone mineral content in post-menopausal women.
  
  
  METHODS
  Twenty-nine post-menopausal women, aged 37-55 years, who had undergone hysterectomy and had experienced the onset of menopausal symptoms within the previous 2 years, were studied before and for 3 years during hormone replacement with oestradiol implants, given at approximately 6-monthly intervals.
  
  
  METHODS
  Total body calcium was measured by prompt gamma neutron activation analysis, spinal trabecular bone mineral density by quantitative computed tomography and radial bone mineral content by single-photon absorptiometry.
  
  
  RESULTS
  There was a significant increase in the mean total body calcium, spinal trabecular bone mineral density and radial bone mineral content over the 3 years of the study. The mean (+/- SEM) percentage change per annum was +2.4% (+/- 0.8) for total body calcium (P < 0.01), +3.3% (+/- 0.6) for spinal trabecular bone mineral density (P < 0.001) and +1.2% (+/- 0.6) for radial bone mineral content (P < 0.05).
  
  
  CONCLUSIONS
  Percutaneous oestradiol replacement therapy prevents menopausal bone loss and is associated with a sustained and significant increase in total body calcium, spinal trabecular bone mineral density and radial bone mineral content over a 3-year treatment period. Oestradiol implants thus have skeletal effects comparable to those of oral or transdermal oestrogens.
authors.affiliation: Department of Medical Physics, Singleton Hospital, Swansea.
authors.forename: S J
authors.initials: SJ
authors.lastname: Ryde
authors.forename: K
authors.initials: K
authors.lastname: Bowen-Simpkins
authors.forename: P
authors.initials: P
authors.lastname: Bowen-Simpkins
authors.forename: W D
authors.initials: WD
authors.lastname: Evans
authors.forename: W D
authors.initials: WD
authors.lastname: Morgan
authors.forename: J E
authors.initials: JE
authors.lastname: Compston
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D015519:Bone Density / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D004343:Drug Implants; D004958:Estradiol / Q000008:administration & dosage*; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D007044:Hysterectomy; D008137:Longitudinal Studies; D008875:Middle Aged; D017698:Postmenopause / Q000378:metabolism / Q000502:physiology*; D011884:Radius / Q000378:metabolism; D013131:Spine / Q000378:metabolism
chemical_list: D004343:Drug Implants; D004958:Estradiol; D002118:Calcium