Feb 23 2006
According to a new study by the National Institutes of Health, people with moderate to severe joint discomfort found that a combination of glucosamine and chondroitin resulted in significant pain and function improvement.
This is the group most in need of treatment and the combination therapy significantly decreased knee pain related to osteoarthritis.
In the study the researchers tested whether glucosamine and chondroitin used separately or in combination, and in comparison to placebo and celecoxib, were effective in reducing pain and improving functional ability in patients with knee joint discomfort.
Jason Theodosakis, M.D., a member of the steering committee for the $14 million NIH study and an advocate for glucosamine and chondroitin supplements, says the treatment costs as little as one dollar a day but patients need to use them for a period of six months before deciding whether their overall symptoms improve.
Many doctors already recommend the supplements along with a quick acting pain reliever and then simply stop the pain reliever as soon as possible.
However the efficiency of glucosamine, chondroitin sulfate could depend on the level of osteoarthritis pain experienced.
Many of participants in the GAIT study found little relief from the popular dietary supplements and in it performed no better than a placebo in relieving osteoarthritis knee pain.
Daniel O. Clegg, M.D., professor of medicine at the University of Utah School of Medicine, chief of rheumatology at the George E. Wahlen Veterans Affairs Medical Center in Salt Lake City, and principal investigator for the national trial, says on the whole supplements were found to be ineffective, other than for patients suffering moderate to severe osteoarthritis knee pain.
Glucosamine is an amino sugar the body produces and distributes in cartilage and other connective tissue, and chondroitin sulfate is a complex carbohydrate that helps cartilage retain water.
They have become popular remedies among osteoarthritis sufferers in recent decades but evidence of the supplements' ability to control pain has been anecdotal.
The five-year, $12.5 million GAIT study was designed to rigorously assess the efficacy and safety of glucosamine and chondroitin sulfate, taken either separately or in combination.
Nearly 1,600 patients with painful knee osteoarthritis were enrolled in the trial and randomly assigned to take placebo, celecoxib (a widely prescribed arthritis pain drug), glucosamine, chondroitin sulfate, or a combination of the two supplements for 24 weeks.
Of the 1,583 study patients, 78 percent were in the mild knee pain subgroup and the remaining 22 percent were in the moderate to severe subgroup.
Celecoxib served as the study's positive control because it is an approved osteoarthritis pain drug and participants would be expected to respond in a predictable way.
For all trial patients, celecoxib proved most effective in providing significant pain relief, with a 70 percent response rate, compared to 64 percent for glucosamine and 65 percent for chondroitin sulfate. Taken in combination, the supplements provided significant relief for 66 percent of patients who receive them.
The response rate in those who took placebo was 60 percent.
According to Clegg in participants in the mild knee pain subgroup, celecoxib proved the most effective, significantly improving pain relief for 70 percent of those who took it, compared to nearly 64 percent for glucosamine, 67 percent for chondroitin sulfate, and 63 percent for the combination of the two.
The placebo produced a 62 percent response rate for people with mild pain.
In patients in the moderate-to-severe knee pain subgroup, however, the combination of the two supplements appeared to be more effective than placebo, significantly reducing pain in 79 percent of those who received it. This is compared with 69 percent who took celecoxib and 54 percent who took placebo. Because only 22 percent of the trial participants were in the moderate-to-severe subgroup, this result should be considered preliminary and further study will be required to confirm these results, according to Clegg.
Study participants were required to have both pain and X-ray evidence of osteoarthritis in their knees.
They were evaluated at the beginning of the trial and at weeks four, eight, 16, and 24, with a positive treatment response defined as a 20 percent or greater decrease in knee pain compared to the start of the study.
More than 20 million Americans have osteoarthritis and oral doses of glucosamine and chondroitin sulfate, derived from animal products, have become popular with arthritis sufferers in the past 20 or so years.
Clegg says people with osteoarthritis need to follow a comprehensive plan for managing their arthritis pain, develop and maintain a healthy lifestyle and consider the use of medications based on the degree of pain experienced.
In a second part of the study, Clegg and other researchers will track whether taking glucosamine and chondroitin sulfate alone and in combination affects progression of knee osteoarthritis.
All participants in the second part of the study had a knee X-ray at the beginning of the trial and will be imaged again at years one and two.
X-rays will be compared and evaluated to assess whether these supplements affect progression of osteoarthritis.
Results of the second part of the study are expected in about a year.
The study is published in the Feb. 23 issue of the New England Journal of Medicine.
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