Effects of percutaneous oestradiol versus oral oestrogens on bone density

In order to compare the effects on bone density of 1.5 mg/day percutaneous 17 beta-oestradiol (E2) and of 0.625 mg/day oral conjugated oestrogens (CEE), 68 women who had undergone hysterectomy were studied. The subjects were randomly allocated to one of three study groups. A total of 15 women dropped out from these groups during the study. The percutaneous group (n = 20) received treatment for 36 months and the oral group (n = 17) for 24 months, while the untreated group (n = 16) served as controls over a period of 24 months. Bone mineral density (BMD) was measured by dual gammagraphic densitometry (Novo 22A densitometer) in the lumbar spine (L2-L4). The percentage gain in the percutaneous group was 1.7% +/- 3.9% after 12 months, 5.6% +/- 2.9% (P < 0.001) after 24 months and 4.7% +/- 3.2% (P < 0.01) after 36 months. In the oral group the gain was 3.5% +/- 13.0% after 12 months and 4.3% +/- 9.2% (P < 0.001) after 24 months. In the untreated group the bone density loss was 6.6% +/- 3.5% (P < 0.001) after 12 months and 9.1% +/- 3.4% (P < 0.001) after 24 months. On the basis of our results we concluded that both 1.5 mg/day percutaneous E2 and 0.625 mg/day oral CEE not only prevented bone loss but also increased BMD, as was confirmed by our findings after 36 and 24 months of treatment, respectively.