Effect of 10 years' hormone replacement therapy on bone mineral content in postmenopausal women

• Published in: Bone (New York, N.Y.) N.Y.), 1996-11, Vol.19 (5), p.191S-193S
• Main Authors: Eiken, P., Kolthoff, N., Nielsen, S. Pors
• Format: Article
• Language: English
• Subjects: Absorptiometry, Photon; Biological and medical sciences; Bone Density - drug effects; Bone mineral density; Bones, joints and connective tissue. Antiinflammatory agents; Double-Blind Method; Estradiol - administration & dosage; Estradiol - pharmacology; Estradiol - therapeutic use; Estrogen; Estrogen Replacement Therapy; Female; Follow-Up Studies; Forearm - physiology; Hormone replacement therapy; Humans; Longitudinal Studies; Lumbar Vertebrae - drug effects; Lumbar Vertebrae - physiology; Medical sciences; Menopause; Norethindrone - administration & dosage; Norethindrone - therapeutic use; Osteoporosis; Osteoporosis, Postmenopausal - drug therapy; Pharmacology. Drug treatments; Progesterone Congeners - administration & dosage; Progesterone Congeners - pharmacology; Progesterone Congeners - therapeutic use; Progestogen
• ISSN: 8756-3282; 1873-2763
• DOI: 10.1016/S8756-3282(96)00266-9

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, LBMD 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. FBMC 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.