Effects of estrogen/androgen therapy on bone mineral density parameters

Although estrogen's efficacy in reversing loss of bone mineral density (BMD ) has been extensively documented, the role of androgens in preserving and restoring BMD is less well understood. Estrogen/androgen (E/A) therapy is e specially important for surgically menopausal women. This population group experiences marked bone loss in response to the dramatic decline in ovarian hormones. The resulting hormonal profile differs significantly from that o f naturally menopausal women. For surgically menopausal women, the relation of estrogens,and androgens and sex hormone binding globulin (SHBG) is of s pecial concern, as the interrelation between these hormones ultimately may reduce hormonal bioavailability. This paper reviews the relation of bone me tabolism to ovarian hormones and the mechanics of BMD loss as well as the t ools available to clinicians to assess bone loss in menopausal women. It fu rther discusses androgen excess in women with polycystic ovary syndrome. Cu rrently available hormonal regimens to preserve bone are described, includi ng estrogen-only therapy, E/A therapy, tibolone and estrogen-progestogen th erapy.