Efficacy of Glucosamine and Chondroitin Sulfate May Depend on Level of Osteoarthritis Pain
In a study published in the New England Journal of Medicine*, the popular dietary supplement combination of glucosamine plus chondroitin sulfate did not provide significant relief from osteoarthritis pain among all participants. However, a smaller subgroup of study participants with moderate-to-severe pain showed significant relief with the combined supplements. This research was funded by the National Center for Complementary and Alternative Medicine (NCCAM) and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), components of the National Institutes of Health (NIH). Researchers led by rheumatologist Daniel O. Clegg, M.D., of the University of Utah, School of Medicine, Salt Lake City, conducted the 4-year study known as the Glucosamine/chondroitin Arthritis Intervention Trial (GAIT) at 16 sites across the United States.
"GAIT is another example of NIH's commitment to exploring the potential of complementary and alternative medicine to prevent and treat disease in a manner that is fair, unbiased, and scientifically rigorous," said Elias A. Zerhouni, M.D., NIH Director.
GAIT enrolled nearly 1,600 participants with documented osteoarthritis of the knee. Participants were randomly assigned to receive one of five treatments daily for 24 weeks: glucosamine alone (1500 mg), chondroitin sulfate alone (1200 mg), glucosamine and chondroitin sulfate combined (same doses), a placebo, or celecoxib (200 mg). Celecoxib is an FDA-approved drug for the management of osteoarthritis pain and served as a positive control for the study. (A positive control is a treatment that investigators expect participants to respond to in a predictable way; it helps validate study results.) A positive response to treatment was defined as a 20 percent or greater reduction in pain at week 24 compared to the start of the study.
The researchers found that participants taking celecoxib experienced statistically significant pain relief, as expected, versus placebo