The effect of low-dose conjugated equine estrogens and cyclic MPA on bone density

OBJECTIVE: to compare the effect of 0.3 and 0.625 mg conjugated equine estrogens on bone mineral density (BMD) in a private practice setting. METHODS: postmenopausal women interested in hormone replacement therapy were prescribed either 0.3 or 0.625 mg conjugated equine estrogens daily with 10 mg medroxyprogesterone acetate days 1-12 of the month. All women were given calcium citrate 1000 mg/day and vitamin D 400 IU/day. DEXA bone mineral density studies of the spine and hip were performed at baseline and 1 year. RESULTS: there was no significant difference in BMD at the spine, the trochanter or the femoral neck compared with baseline in either the 0.625 or 0.3 mg group. The mean percent increase in BMD for the 0.3 versus 0.625 mg group was: spine 2.6 versus 3.8%, femoral neck 1.8 versus 1.5%, and trochanter 0.5 versus 2.6%. CONCLUSION: both the 0.625 mg dose and the 0.3 mg dose of conjugated equine estrogens preserved BMD at the spine and hip over one year in early postmenopausal women who were also given cyclic medroxyprogesterone acetate, calcium citrate and vitamin D.