A. Grey et al., MEDROXYPROGESTERONE ACETATE ENHANCES THE SPINAL BONE-MINERAL DENSITY RESPONSE TO ESTROGEN IN LATE POSTMENOPAUSAL WOMEN, Clinical endocrinology, 44(3), 1996, pp. 293-296
OBJECTIVES The relative contributions of administered oestrogen and pr
ogestin to protection of the post-menopausal skeleton remain unclear.
We have compared the effect on spinal bone mineral density of continuo
us combined oestrogen/medroxyprogesterone therapy with that of unoppos
ed oestrogen in late post-menopausal women. DESIGN Observational study
. SUBJECTS Seventy-three osteoporotic post-menopausal women attending
the Auckland Hospital Bone Clinic. Twenty-three hysterectomized women
were treated with unopposed oestrogen (0.625 mg oral conjugated oestro
gens daily), and 50 non-hysterectomized women were treated with contin
uous combined oestrogen/medroxyprogesterone therapy (5 mg medroxyproge
sterone acetate and 0.625 mg oral conjugated oestrogens daily). MEASUR
EMENTS Baseline and one-year measurements of lumbar spine bone mineral
density were performed using dual-energy X-ray absorptiometry. RESULT
S After one year of therapy, spinal bone mineral density increased by
6.6% (95% confidence interval 5.6-7.6, P < 0.001 vs baseline) in the c
ombined oestrogen/ medroxyprogesterone therapy group, compared to 4.0%
(Cl 2.4-5.7, P < 0.001 vs baseline) in the unopposed oestrogen group
(difference between means 2.6% (CI 0.8-4.4, P < 0.01). CONCLUSION In o
steoporotic post-menopausal women, one year of continuous combined oes
trogen/medroxyprogesterone therapy is associated with a 65% greater in
crement in spinal bone mineral density than is observed in response to
unopposed oestrogen. The prescription of combined oestrogen/progestin
therapy should be considered in osteoporotic post-menopausal women wh
o have undergone hysterectomy, in order to maximize the skeletal prote
ction provided by hormone replacement therapy.