Effect of progestin therapy on cortical and trabecular bone: comparison with estrogen

purpose: To determine the effect of progestin therapy on bone mineral density in postmenopausal women and to compare its effects to those of estrogen. subjects and methods: A prospective, randomized clinical trial was performed in 81 postmenopausal women aged 51.7 ± 4.4 years (mean ± SD). They were assigned to one of four groups: Provera® 20 mg, Premarin® 0.6 mg, Premarin 0.3 mg plus Provera 10 mg, and a placebo. In addition, all women received calcium supplementation, if necessary, to a calcium intake of 1,000 mg/day. We used single- and dual-photon absorpiometry, metacarpal radiogrammetry, and computed axial tomography to measure bone mineral density in the total skeleton, spine, radius, and metacarpal. results: Women receiving placebo lost bone at all sites (p