Glucosamine, Chondroitin Sulfate May Be Useful for Knee OA Patients

Newswise — Glucosamine and chondroitin sulfate may be an effective combination in reducing pain associated with osteoarthritis of the knee, according to research presented this week at the American College of Rheumatology Annual Scientific Meeting in San Diego, California.

Glucosamine is an amino sugar naturally produced by the body and widely distributed to the connective tissues, including cartilage. The body also produces chondroitin sulfate, a complex carbohydrate molecule which, among its other roles, helps retain water in cartilage. Over the past 25 years, oral glucosamine and chondroitin sulfate, derived from animal products, have become popular dietary supplements with patients attempting to combat the cartilage wear and tear associated with osteoarthritis. The precise biologic mechanisms that enable oral supplements to emulate the body's natural products, however, remain undefined.

GAIT (The Glucosamine/Chondroitin Arthritis Intervention Trial), funded by the National Institutes of Health, was designed to rigorously assess the effectiveness and safety of these supplements when taken separately or in combination. Almost 1,600 patients with painful knee osteoarthritis were recruited from 16 U.S. academic rheumatology centers for the study. The patients, who had experienced significant knee pain for more than six months and had x-ray evidence of knee osteoarthritis, were evaluated at the beginning of the study, and at weeks 4, 8, 16 and 24. Each was randomly assigned to receive glucosamine hydrochloride, sodium chondroitin sulfate, both supplements, celecoxib, or placebo therapy and allowed up to 4,000 mg daily of acetaminophen. The primary outcome measure was a 20 percent improvement in knee pain by week 24.

"As expected, celecoxib improved knee pain in patients with osteoarthritis. For the study as a whole, the supplements were not shown to be effective; however, an exploratory analysis suggested that the combination of glucosamine and chondroitin sulfate might be effective in osteoarthritis patients who had moderate to severe knee pain," stated Daniel O. Clegg, MD, Chief, Division of Rheumatology, University of Utah School of Medicine, Salt Lake City, Utah. Adverse events that were seen in GAIT were generally mild and evenly distributed across all groups. Dr. Clegg continued, "Given the results of this study, patients might want to discuss treatment options with their physicians."

The American College of Rheumatology is the professional organization for rheumatologists and health professionals who share a dedication to healing, preventing disability, and curing arthritis and related rheumatic and musculoskeletal diseases. For more information on the ACR's annual meeting, see http://www.rheumatology.org/annual.