Efficacy Of
Glucosamine And Chondroitin Sulfate May Depend On Level Of Osteoarthritis Pain
2006-02-23 - NIH/National Center for Complementary and Alternative Medicine
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--about 70 percent of those taking celecoxib versus 60 percent taking placebo had a 20 percent or greater pain reduction. For all participants, there were no significant differences between the other treatments tested and placebo. However, for participants in the moderate-to-severe pain subgroup, glucosamine combined with chondroitin sulfate provided statistically significant pain relief compared to placebo--about 79 percent in this group had a 20 percent or greater pain reduction compared to 54 percent for placebo. In the subgroup of participants with mild pain, glucosamine and chondroitin sulfate together or alone did not provide statistically significant relief compared to placebo.
"This rigorous, large-scale study showed that the combination of glucosamine and chondroitin sulfate appeared to help people with moderate-to-severe pain from knee osteoarthritis, but not those with mild pain," said Stephen E. Straus, M.D., NCCAM Director. "It is important to study dietary supplements with well-designed research in order to find out what works and what does not."
"Because of the small size of the moderate-to-severe pain subgroup, the findings in this group for glucosamine plus chondroitin sulfate should be considered preliminary and need to be confirmed in a study designed for this purpose," said Dr. Clegg, Professor of Medicine and Chief of Rheumatology at the University of Utah, School of Medicine.
On entering the study, a participant's level of pain was assessed as either mild or moderate to severe using standard pain assessment tools and scales, such as the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Of the 1,583 study participants, 78 percent were in the mild pain subgroup and the other 22 percent were in the moderate-to-severe pain subgroup. Level of pain was evaluated at weeks 4, 8, 16, and 24 using the WOMAC scale and other tools. In addition to taking their daily study treatment, participants could take up to 4000 mg of acetaminophen daily for pain, except for the 24 hours before they were assessed by study staff. The use of acetaminophen, however, was low, overall averaging fewer than two 500 mg tablets per day. Participants could not take other non-steroidal anti-inflammatory medicines or narcotic (opioid-based) pain relievers during the study.
"More than 20 million Americans have osteoarthritis, making it a frequent cause of physical disability among adults," said Stephen I. Katz, M.D., Ph.D., NIAMS Director. "We are excited to support studies looking at new treatment options that could improve the symptoms and quality of life of people with osteoarthritis."
GAIT was conducted under an Investigational New Drug application filed with the U.S. Food and Drug Administration. Thus, all of the products used in the study were subject to the FDA's pharmaceutical regulations and evaluated and manufactured by an FDA-licensed clinical research pharmacy center. The glucosamine and chondroitin sulfate used were tested for purity, potency, quality, and consistency among batches. Products were retested for stability throughout the study. The dosages selected were based on the prevailing doses in the scientific literature. Few side effects from any of the treatments were reported. Those reported were generally mild, such as upset stomach, and distributed evenly across the treatment groups.
"The GAIT team's goal was to assess whether glucosamine and chondroitin sulfate, which we saw our osteoarthritis patients using, provided pain relief," said Dr. Clegg. "I urge people with osteoarthritis to follow a comprehensive plan for managing their arthritis pain--eat right, exercise, lose excess weight, and talk to your physician about appropriate treatment options."
The GAIT team continues their research with a smaller study to see whether glucosamine and chondroitin sulfate can alter the progression of osteoarthritis, such as delaying the narrowing of the joint spaces. About one-half of the participants in the larger GAIT study were eligible to enroll in this ancillary study. The results are expected in about a year.
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Study Shows
Supplements Relieve Osteoarthritis PainCombination of Glucosamine and Chondroitin Helps Patients Suffering the Most
--NIH-Sponsored Trial Supports Previous Research on Pain Relief--
WASHINGTON, D.C., February 22, 2006 — Offering hope for millions of people who suffer the most from osteoarthritis, a study published in the New England Journal of Medicine (NEJM) has found that the combined use of two dietary supplements—glucosamine and chondroitin—provided significant pain relief from the most common form of arthritis.
The clinical trial, sponsored by the National Institutes of Health (NIH), found that using a combination of the two supplements "significantly decreased" knee pain in osteoarthritis patients experiencing moderate-to-severe pain. Results of the Glucosamine/chondroitin Arthritis Intervention Trial (GAIT) appear in the Feb. 23 issue of NEJM.
"GAIT adds to a growing body of scientific evidence that shows the two supplements can safely alleviate pain from osteoarthritis," said Andrew Shao, Ph.D., vice president of scientific and regulatory affairs at the Council for Responsible Nutrition. "This rigorous clinical trial offers strong evidence that glucosamine and chondroitin can provide significant relief from knee pain for those who suffer the most from osteoarthritis," Dr. Shao said.
Osteoarthritis—a chronic condition known as the "wear-and-tear" kind of arthritis—afflicts 21 million Americans each year, a large percentage of whom suffer moderate-to-severe knee and joint pain.
The six-month GAIT study involved 1,500 osteoarthritis patients who were given a placebo or daily doses of 1,500/mg of glucosamine hydrochloride and/or 1,200 mg of chondroitin sulfate or 200 mg of the common prescription pain medication celecoxib. In the NEJM article, Daniel O. Clegg, M.D., the principal author, and his colleagues note that an analysis of patients with moderate-to-severe pain "demonstrated that combination therapy significantly decreased knee pain related to osteoarthritis."
The GAIT findings are supported by the vast majority of more than 50 published clinical trials that have demonstrated the safety and benefit of the two supplements, Dr. Shao said, adding that glucosamine and chondroitin may help others at risk for osteoarthritis or those experiencing joint discomfort, including athletes in high-impact sports such as basketball or running.
"We believe that the results from this study not only indicate that more research is needed to determine the full potential of glucosamine and chondroitin, but also to reconfirm that these supplements can help the growing number of Americans with joint problems reduce the pain of osteoarthritis," he said.
The Council for Responsible Nutrition (CRN), founded in 1973, is a Washington, D.C.-based trade association representing dietary supplement industry ingredient suppliers and manufacturers. CRN members adhere to a strong code of ethics, comply with dosage limits and manufacture dietary supplements to high quality standards under good manufacturing practices. For more information visit the CRN website
http://www.crnusa.org/.
Note to Editors: To arrange an interview with Andrew Shao, Ph.D., CRN's vice president of scientific and regulatory affairs, or John Hathcock, Ph.D., CRN's vice president of scientific and international affairs, please contact Judy Blatman at 202-204-7962
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