Estrogens and SERMs in the treatment of osteoporosis.

Estrogen deficiency is the major determinant of bone loss, not only in the first years postmenopause, but also throughout the entire life and in the e lderly. Major progress in the knowledge of cellular actions of estrogens ha s been made leading to a better understanding of the underlying mechanisms of different estrogen-deficiency related diseases such as osteoporosis, ath erosclerosis and also maybe cerebral aging. Estrogen replacement therapy re mains the first choice treatment in the prevention of postmenopausal osteop orosis, but the continuous aging process of the female population raises th e question of a better strategy of action in a mere efficient prevention of hip fractures. Moreover, the potential gynecological effects of estrogens are likely to Limit their indications or long-term use. The development of new compounds, called SERMs (selective estrogen receptor modulators), with both agonist and antagonist estrogen actions, in particular with no negativ e effects on the uterus and the breast opens new therapeutical insights int o the prevention of postmenopausal osteoporosis.