title: Effect of 10 years' hormone replacement therapy on bone mineral content in postmenopausal women.
abstract: The purpose of this study was to investigate the effects of 10 years of hormone replacement therapy (HRT) in postmenopausal women on bone mineral density of the lumbar spine (L-BMD) and bone mineral content of the distal forearm (F-BMC). A total of 151 women were enrolled in the study, 100 of whom were randomized to receive oral HRT (equally divided between a continuous combined and a sequential treatment regimen), with the remaining 51 receiving placebo or no treatment. The study was double-blind for the first 24 months, followed by 8 years of open-label follow-up. Total treatment duration was 10 years. At the end of 10 years, 38% of women randomized to continuous combined HRT remained on therapy compared with 22% of those who had received sequential HRT and 49% of the untreated group. A further 18% of women originally randomized to HRT had switched to other regimens. After 10 years of therapy, L-BMD was found to be significantly higher in HRT-treated women than in those who remained untreated (14.5%; p < 0.001), corresponding to an increase in L-BMD of 13.1% from baseline values on HRT compared with a reduction in L-BMD of 4.7% without therapy. L-BMD increased by 15.9% in women receiving continuous combined therapy compared with 11.1% in those on sequential HRT; however, intergroup differences were not statistically significant. F-BMC decreased by 0.7% over the 10 year period in the HRT treatment groups compared with a reduction of 17.6% in untreated women (p < 0.001). Mean F-BMC was 20.3% higher in women who had received HRT than in those who had not received therapy at the end of the 10 year follow-up. In conclusion, 10 years of treatment with HRT resulted in a substantial increase in L-BMD, with F-BMC also significantly higher in the HRT group than in untreated women. These results confirm that long-term HRT exerts a continuous effect against bone loss in postmenopausal women.
authors.affiliation: Department of Clinical Physiology, Hillerød Hospital, Denmark.
authors.forename: P
authors.initials: P
authors.lastname: Eiken
authors.forename: N
authors.initials: N
authors.lastname: Kolthoff
authors.forename: S P
authors.initials: SP
authors.lastname: Nielsen
mesh_terms: D015502:Absorptiometry, Photon; D015519:Bone Density / Q000187:drug effects*; D004311:Double-Blind Method; D004958:Estradiol / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D015914:Estrogen Replacement Therapy; D005260:Female; D005500:Follow-Up Studies; D005542:Forearm / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008159:Lumbar Vertebrae / Q000187:drug effects / Q000502:physiology; D009640:Norethindrone / Q000008:administration & dosage / Q000627:therapeutic use; D015663:Osteoporosis, Postmenopausal / Q000188:drug therapy*; D045167:Progesterone Congeners / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*
chemical_list: D045167:Progesterone Congeners; D004958:Estradiol; D009640:Norethindrone