Author:

Abstract:

The beneficial effect of classical hormone replacement therapy (HRT) on bone mineral density (BMD) at several skeletal sites has been documented in a number of prospective studies. However, recent data from a very large randomized trial indicate that, despite an unequivocal anti-fracture effect, HRT is associated with an excess of cardiovascular disease and breast cancer. Hence, there is a growing interest in het development of compounds exhibiting tissue-specific estrogenic or antiestrogenic effects. Raloxifene is the only SERM currently licensed for use in osteoporosis. In healthy women in the early post-menopause, raloxifene treatment entails a modest increase in BMD at the spine, hip and total body. In a large randomized trial in women with osteoporosis, raloxifene (60 mg daily) reduces the vertebral fracture rate by about 40%, but no reduction in hip fracture rate has been documented. In addition, a substantial protective effect against breast cancer has emerged in osteoporotic women, and, unlike HRT, raloxifene does not stimulate the endometrium and does not cause uterine bleeding. But, similarly to HRT, there is a two-tothreefold increase in the relative risk of venous thromboembolism. Tibolone is a hormonal compound with tissue-specific estrogenic effects. Similarly to raloxifene, tibolone prevents bone loss in early postmenopausal women, but no fracture data are available as yet. Unlike raloxifene, tibolone clearly improves vasomotor symptoms and has a positive impact on the sexual response. Fyto-estrogens, including the isoflavones, attract considerable attention, because of their mild tissue-specific estrogen-like effects. However, it is too early to assess its potential antiosteoporotic effect.