Researchers at Cedars-Sinai Medical Center are now enrolling patients in a large multi-center clinical trial to determine whether two popular dietary supplements – glucosamine and chondroitin sulfate – reduce the knee pain associated with osteoarthritis (OA). The disease causes pain, deformity and enlargement of the joints and is diagnosed in almost twice as many women as men.
“This study is the first and largest of its kind to evaluate whether these popular supplements actually work to alleviate knee pain in people afflicted with this disease,” said Michael Weisman, M.D., Principal Investigator and Director of the Division of Rheumatology at Cedars-Sinai Medical Center.
Marketed as dietary supplements, glucosamine and chondroitin sulfate have been widely reported as effective alternative treatments for arthritis. For the last two decades, the supplements have been used extensively in Europe to treat OA. Glucosamine is a substance in the body that helps to form cartilage. Chondroitin sulfate is part of a large protein molecule that gives cartilage its elasticity. Both glucosamine and chondroitin sulfate are believed to play a role in cartilage maintenance and repair.
To date, however, only a few small studies have examined the effectiveness of glucosamine and chondroitin sulfate to reduce OA knee pain. The majority of these studies were conducted in Europe and reported that the compounds relieved pain just as well as simple analgesic drugs such as acetaminophen or non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen. But both acetaminophen and NSAIDs provide only minimal improvement in joint pain and function. Moreover, when used over the long-term, NSAIDs have been found to increase the risk of peptic ulcer perforations, hemorrhaging, hospitalization and death in patients 65-years of age or older.
“Given the limitations of these drugs, patients often ask us about the safety and effectiveness of glucosamine and chondroitin sulfate, but we have little evidence in which to guide our patients,” said Dr. Weisman. “This large trial conducted at several centers will provide definitive results about whether these supplements actually work to reduce pain and reduce the loss of cartilage associated with OA.”
To settle the safety and efficacy issues surrounding glucosamine and chondroitin sulfate, the National Institutes of Health recently launched a $6.6 million dollar study. The study aims to recruit more than 1,000 patients at nine centers across the country. Cedars-Sinai began recruiting patients in December 2000.
Patients who volunteer to participate in the study will be examined and have x-rays taken to verify the presence of OA. Once OA is confirmed, patients will be randomly assigned to one of four groups who will take: glucosamine alone; glucosamine plus chondroitin sulfate; Celebrex(r) (celecoxib), an anti-inflammatory drug; or a placebo. Patients will receive a monthly supply of capsules and must take the required dosage daily. Patients may choose to participate in the study for six months or can take part in a two year study that will evaluate whether the supplements taken over a longer period of time actually improve OA of the knee.
The study is open to men and women 40 years of age and older who have been medically diagnosed with osteoarthritis of the knee. The patients must have had OA symptoms for at least six months prior to participating in the study and must have no concurrent medical diseases such as rheumatoid arthritis or lupus. Patients must also not be pregnant, diabetic, or have allergies to non-steroidal anti-inflammatory drugs (NSAID’s), and/or shellfish.
Those individuals interested in participating may contact Dr. Weisman’s clinical research coordinator, Karen Yee in Cedars-Sinai’s Rheumatology Division at 310-423-2693; or Dr. David Silver’s study coordinator, Carol Joseph at 310-358-5757.