NATIONAL CENTER FOR COMPLEMENTARY AND ALTERNATIVE MEDICINE
Glucosamine and Chondroitin for Cartilage Loss
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A recent study of the dietary supplements glucosamine and chondroitin sulfate (CS), alone and in combination, for treating cartilage loss in knee osteoarthritis has found that the active-treatment group did not fare better than the placebo group. Interpreting these results is complicated, however, by the placebo group having lost a smaller amount of cartilage than was expected, based on prior research.
The findings, released in September 2008, are from an ancillary (secondary) study in the Glucosamine/chondroitin Arthritis Intervention Trial, or GAIT. This is a large, prospective, randomized clinical trial supported by NCCAM and the National Institute of Arthritis and Musculoskeletal and Skin Diseases, and led at the University of Utah School of Medicine, Salt Lake City.
Previous GAIT results, reported in 2006, centered on pain in osteoarthritis. In that study, overall, glucosamine and CS did not provide significant pain relief for all participants. However, when combined, these supplements may have provided relief for a small subgroup with moderate-to-severe pain.
The 2008 results are from a 2-year study of a subset of GAIT participants. Five randomized groups received either 500 milligrams (mg) of glucosamine three times daily, 400 mg of CS three times daily, glucosamine plus CS, 200 mg of celecoxib daily, or placebo. Using an x-ray protocol, the researchers measured loss of cartilage, represented by loss of joint space width, upon entrance to the study and at 1- and 2-year benchmarks.
Allen Sawitzke, M.D., associate professor of internal medicine at the University of Utah, led the ancillary study, and Complementary and Alternative Medicine asked him to comment to clinicians. He said, "We have found these agents to be generally safe and well tolerated. To date, the evidence supporting relief of pain is stronger than that for slowing of cartilage loss. Hence, a short trial for relief of pain can help each patient make his own decision."
Daniel Clegg, M.D., principal investigator for GAIT and professor of medicine and chief of rheumatology at the University of Utah, noted that despite limitations in the ancillary study, it has yielded new insights on the progression of osteoarthritis, techniques for reliably measuring structural damage from the disease, the effects of these supplements, and predictors for who may respond best in future studies.
To read more, go to www.nih.gov/news/health/sep2008/nccam-29.htm.
Reference
- Sawitzke AD, Shi H, Finco MF, et al. The effect of glucosamine and/or chondroitin sulfate on the progression of knee osteoarthritis: a report from the glucosamine/chondroitin arthritis intervention trial. Arthritis & Rheumatism. 2008;58(10):3183–3191.
