Drug May Help Prevent Women's Osteoarthritis

Calcitonin is already used to fight age-linked bone loss, researchers say

By Randy Dotinga
HealthDay Reporter
Monday, July 30, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

MONDAY, July 30 (HealthDay News) -- Preliminary research in rats suggests that an existing drug could help older women stop osteoarthritis in its tracks.

The drug, known as calcitonin, is currently used to treat osteoporosis. According to tests in female rats, it shows promise as a possible treatment for osteoarthritis in older, postmenopausal women.

Patients "should be hopeful," said study co-author Morten A. Karsdal, head of pharmacology at Nordic Bioscience, a biotech company that is studying the drug's prospects as an arthritis treatment.

However, testing in humans won't end for another three years, and there's no guarantee that the drug will work as well in humans as in rats.

The study is published in the August issue of the journal Arthritis & Rheumatism.

Osteoarthritis affects an estimated 10 percent of Americans, and 80 percent of those over 55; women are especially vulnerable.

Hips and knees can be especially susceptible, said Dr. J.C. Gallagher, director of the Bone Metabolism Unit at Creighton University Medical School in Omaha, Neb. "For many, pain on exercise is the major problem. As a result, they stop exercising, and this leads to an increase in body weight which increases the 'load' on the joints and worsens the arthritis."

There are numerous treatments to relieve osteoarthritis pain but none to stop the wear and tear on the bone, joints and cartilage.

Karsdal said it is important to treat both loss of bone and loss of cartilage, the elastic tissue that helps bones tolerate moving against each other. "When bone turnover increases after menopause, due to lower estrogen production, a secondary effect is seen on cartilage, more cartilage is lost," Karsdal said. "Ideally, all drugs that may be developed for osteoarthritis will be able to affect both bone and cartilage, as both are in disequilibrium in osteoarthritis."

In the new study, researchers removed the ovaries of female rats, turning them into rough equivalents of postmenopausal women -- at least when it comes to their skeletons.