A synthetic compound called "estren" helped build bone, without affecting the reproductive organs of both female and male mice, a new study reports. If the same holds true for humans, these findings may suggest an alternative to standard hormone replacement therapy for treating osteoporosis, the authors say. The study appears in the journal Science, published by the American Association for the Advancement of Science.

Osteoporosis affects millions of people worldwide, many of them post-menopausal women.

"For a long time we have been giving hormone replacement to women, based on the evidence that estrogens are effective in preventing osteoporosis. The big assumption was that estrogen worked the same way in all the tissues," said study author Stavros Manolagas of the University of Arkansas for Medical Sciences and Central Arkansas Veterans Health Care System

Along with their bone-related benefits, however, estrogen supplements can also have unwanted effects in the body's reproductive tissues, according to Manolagas. For example, they can modestly increase the risk of breast and uterine cancer. Several months ago, a major clinical study on the long-term use of estrogen plus progesterone found that these risks, as well as others, outweighed the therapy's benefits. The news left many women in a quandary about whether to continue their therapy.

"Our study shows you can have the benefits [of estrogen] on non-reproductive tissues, without having the side effects," Manolagas said. "This is a brand new page of pharmacology."

Estren may be useful for preventing osteoporosis in men as well as women. Because androgen stimulates prostate cancer, men with the disease typically have their prostate removed or take androgen-inhibiting drugs, leaving them vulnerable to osteoporosis.

"It's very exciting that t
'"/>

Contact: Lisa Onaga
lonaga@aaas.org
202-326-7088
American Association for the Advancement of Science
24-Oct-2002