Hope for male osteoporosis patients
Jerusalem, January 1, 2001 - Osteoporosis is an affliction commonly identified with women, however there are millions of men in the world who also suffer from it. Estimates are that the number of men with this disease is one-fourth that of women. Despite this, there has been no solution thus far to this epidemic among men. However, researchers in the Bone Laboratory in the Institute of Dental Sciences at the Hebrew University of Jerusalem Faculty of Dental Medicine are developing new therapeutic and preventive approaches to treat men suffering from osteoporosis.
The Hebrew University researchers, headed by Professor Itai Bab, are developing preparations that stimulate bone building based on naturally occurring hormones that regulate bone formation.
Professor Bab's research team in Jerusalem and the Division of Bone and Mineral Metabolism at the Harvard Medical School in Boston, headed by Professors Michael Chorev and Michael Rosenblatt, have jointly reported that the Osteogenic Growth Peptide (OGP, discovered a decade ago in the Hebrew University Bone Laboratory) and the Parathyroid Hormone (PTH) stimulate bone building in osteoporotic mice. Drugs under development based on these preparations can prevent bone loss and restore the porous skeleton.
Osteoporosis is a disease that weakens bones resulting from a decrease in bone density. This, in turn, results in multiple fractures, which in many cases lead to severe disability and complications that may even cause death. The decrease in bone density results from internal destruction of the bone tissue. In every person this tissue is being continuously remodeled and rebuilt throughout life to cope with changing mechanical loads. This process consists of two stages: resorption (destruction) of bone tissue and its replacement by newly formed bone. Specialized cells carry out both the destruction and building of bone.
This remodeling takes place in multiple minute foci and migrates from site to site. At any given time about a tenth of the total bone tissue in the body participates in the remodeling. Until menopause in women and at an older age in men (10-15 years later), the remodeling process is balanced; that is, the total amount of bone that is built is equal to the amount of bone lost, thus maintaining the bone density. Thereafter, the remodeling is unbalanced -- the amount of bone destroyed is greater than that built, and the density drops.
The reasons for the imbalance are different in men and women. Menopause in women triggers a steep rise in the number of bone destroying cells and in their activity. In men, there is a slow and longer decrease in the number and activity of bone building cells, which is especially pronounced in prostate cancer patients treated with sex hormone inhibitors. These differences suggest different treatment approaches. Indeed, women are currently benefited from a new generation of drugs that inhibit the activity of the bone destroying cells and prevent the decrease in bone density. On the other hand, drugs that stimulate bone formation in osteoporotic men are so far unavailable.
Medicines based on the research by the Hebrew University scientists are now under development by pharmaceutical companies in the U.S. and Europe to combat osteoporosis in men and also as complementary drugs to antiresorptive agents in women. However, several years are still required for the efficiency of these newly developed drugs to be demonstrated in clinical trials in humans.
For further information: Jerry Barach, Dept. of Media Relations, 972-2-5882904 or 972-2-5864772 (home).