Calcitonin May Fight Osteoarthritis

July 30, 2007 -- A drug currently used to treat osteoporosis may also help protect the bone and slow or perhaps even halt the progression of osteoarthritis, according to early research.

A new study shows treatment with calcitonin, a hormone, effectively prevented erosion of knee cartilage in rat models of osteoarthritis. Osteoarthritis is also known as degenerative joint disease and is related to cartilage breakdown in the joints which can lead to joint damage.

Calcitonin is currently used to treat Paget’s disease of the bone and osteoporosis, as previous studies have shown that the hormone reduces bone loss. But researchers say these results suggest that calcitonin may also help prevent the joint destruction associated with osteoarthritis (OA).

New Option for OA

Osteoarthritis is the most common joint disorder and affects more than 10% of Americans. Treatment usually addresses easing the pain caused by joint stiffness and inflammation associated with osteoarthritis.

To date, no drug has been approved to prevent the gradual loss of cartilage caused by the disease. But a new understanding of the progression of the disease in recent years has prompted a surge of interest in developing disease-modifying osteoarthritis drugs aimed at potentially preventing the disease in those at risk, such as postmenopausal women.

In the study, published in Arthritis & Rheumatism, researchers compared the effects of treating female rats that had their ovaries removed with estrogen alone and estrogen plus calcitonin.

Loss of estrogen from age or other causes increases the risk of osteoporosis. Other research has suggested that hormone replacement therapy helps protect postmenopausal women from osteoarthritis. This study showed that estrogen therapy and calcitonin given to rats helped reduce the rise in compounds indicative of joint destruction of osteoarthritis.

Calcitonin and estrogen also worked effectively in protecting against surface erosions of joint cartilage.

“Calcitonin treatment may counter the acceleration of cartilage degradation and the related rise of surface erosions,” writes researcher Bodil-Cecilie Sondergaard, of Nordic Bioscience Diagnostics in Herlev, Denmark, and colleagues.

Researchers say these results are only preliminary, but they suggest that calcitonin merits further research in human clinical trials.