WASHINGTON--Two branches of the National Institutes of Health (NIH)--the National Center for Complementary and Alternative Medicine (NCCAM) and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)--are about to begin a large-scale trial on the effects of glucosamine and chondroitin on osteoarthritis. Study enrollment is currently open.

The study was funded by NCCAM through $14 million in appropriated monies from Congress. "It's the largest clinical trial that NCCAM has funded to date," said Anita Greene, a press officer at NCCAM. "Generally, when our center makes funding decisions, it is based on the public health needs and the particular medical condition. Osteoarthritis does affect a large number of Americans." She added that there was also a public need for this study because glucosamine and chondroitin are sold over the counter and a vast amount of people are self-treating despite the "little definitive evidence" to show whether these supplements are effective, especially over the long-term.

The first phase of the study has already been completed: the study design was refined, personnel were hired, operating policies and procedures were developed, the electronic data entry system was tested, Institute Review Board approvals were obtained, and the Investigational New Drug exemption from the Food and Drug Administration (FDA) was secured. The second phase includes enrollment and testing, which will take approximately 33 months. The third phase will last six months while data is cleaned up, analyzed and prepared for the final report due in March 2005.

The 24-week, placebo-controlled, parallel, double-blind, five-arm clinical trial will follow 1,588 volunteers across 13 clinical centers. The efficacy of glucosamine alone, chondroitin alone and a combination of the two will be used to treat knee pain. Patients will also be able to take acetaminophen if they experience severe pain. The glucosamine hydrochloride provided in the study is manufactured by Waukegan, Ill.-based Pfanstiehl Laboratories; chondroitin sulfate is donated and manufactured by Barcelona, Spain-based Bioiberica. Encapsulated formulas will be used in the study, a conventional method best-used during a double-blind, placebo-controlled trial.

In addition, a "sub-study" will take place, where approximately one-half of the volunteers will receive blinded treatment for an additional 18 months as they undergo knee radiographs. These films will be compared and evaluated for significant structural changes among the five groups.

"I think you'll see very acceptable results from glucosamine, and I think you'll see acceptable results from glucosamine and chondroitin used together," said Jim France, a chemist and director of sales and marketing at Wilkes Resources Inc., which represents Pfanstiehl. "One of the interesting things is whether there will be just as an acceptable response with chondroitin by itself. Glucosamine is the real functional agent here. Chondroitin may well be a contributory agent, but not to the extent of glucosamine by itself." He added that the supplements have a synergistic effect on one another, even though there is controversy in the industry regarding that effect.

"Nobody has the answer, much like who was elected President in Florida," he said. "Hopefully, these studies will show that a combination product offers a real benefit over a singular product." Calls to Bioiberica were unreturned by press time.

Daniel Clegg, M.D., professor of medicine and chief of the Division of Rheumatology at the University of Utah will direct the coordinating center and oversee the operations of the 13 additional centers. For additional information, visit http://nccam.nih.gov.