Objectives: Although oestrogen/progestin therapy is effective prophylaxis against post-menopausal osteoporosis, its efficacy in the treatment of established disease is uncertain. In addition, cyclical oestrogen/progestin regimens are associated with low rates of patient acceptance. The present study assesses the acceptability of, and skeletal response to, continuous combined hormone replacement therapy in osteoporotic late post-menopausal women.
Design: Retrospective, controlled study.
Patients: One hundred and four osteoporotic late postmenopausal women treated with continuous combined hormone replacement therapy (5 mg medroxyprogesterone acetate daily and either 0.625 mg oral conjugated oestrogens for 50 micrograms transdermal oestradiol daily) were followed for an average of 1 year (range 2-38 months). Control subjects were 19 healthy normal women matched for menopausal age and weight.
Measurements: Adverse effects and compliance rate were monitored. Baseline and 1-year measurements of lumbar spine bone mineral density (BMD) were performed using dual-energy X-ray absorptiometry in 51 women, 22 of whom also had measurements at 2 years. Twenty-eight women had proximal femur scans at baseline and 1 year.
Results: Eighty-six per cent of women continued to take continuous combined hormone replacement therapy at the end of follow-up. Mastalgia (44%) and vaginal bleeding (29%), the most common side-effects, were minor and self-limiting in virtually all women. Spinal BMD increased by 7.1 +/- 0.8% (mean +/- SEM P < 0.001) at 1 year and by 8.9 +/- 1.5% (P < 0.001) at 2 years. In the proximal femur, BMD increased by 2.9 +/- 0.9% at the femoral neck (P = 0.01) and by 2.5 +/- 0.9% (P = 0.001) at the trochanter at 1 year. BMD tended to decline in the control group. Among the women taking hormone replacement therapy, the increase in spinal BMD was similar in those treated with 0.3-0.44 mg/day of conjugated equine oestrogens to those receiving 0.45-0.625 mg/day.
Conclusion: Continuous combined hormone replacement therapy is an acceptable therapy to osteoporotic late post-menopausal women and produces substantial increases in lumbar spine and proximal femoral bone mineral density.