Glucosamine, Chondroitin May Be Linked to Pain Level
The dietary supplements glucosamine and chondroitin, taken by millions of people with aching knees, do not help everyone with osteoarthritis, according to research reported in the New England Journal of Medicine.
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).
“More than 20 million Americans have osteoarthritis, making it a frequent cause of physical disability among adults,” says Dr. Stephen I. Katz, 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.”
Additionally, one of the physicians questions whether the study used the correct supplement combination to determine their effectiveness in fighting pain.
The study enrolled 1,583 people, averaging 59 years of age, with knee pain caused by osteoarthritis, the wear-and-tear condition that often occurs in older people.
Participants were divided into five groups: one group received 1,500 milligrams daily of glucosamine; another received 1,200 milligrams of chondroitin; a third group received both glucosamine and chondroitin; a fourth group received 200 milligrams of the prescription painkiller Celebrex; and the last group received a placebo (inactive substance).
The goal was to reduce knee pain by at least 20 percent.
Overall, the two supplements were not significantly better than placebo in reaching that 20 percent goal.
But, the researchers add, there were indications some people with more severe pain might have benefited from the supplements.
Many more people with moderate to severe pain reported benefit from the combination of both supplements (79.2 percent) than with placebo (54.3 percent). And it is that response that interested study author Dr. Daniel O. Clegg, chief of rheumatology at the University of Utah.
"That group needs to be studied better, and that is what I will pursue as a scientist," says Dr. Clegg.
His advice as a practicing physician to pain sufferers who might be considering the supplements is cautious, and addressed specifically to those with osteoarthritis.
"I would lose weight, exercise, take nonprescription pain medicine, and then an NSAID [nonsteroidal anti-inflammatory drug] if necessary," explains Dr. Clegg.
"Then if I still had more severe pain, I would discuss with my physician the potential for supplements."
If the decision is to take supplements, "I would probably use the combination" of glucosamine and chondroitin, says Dr. Clegg. "Glucosamine, if it works, seems to work best in [this] combination."
A different view was offered by Dr. Marc C. Hochberg, a professor of medicine and head of the division of rheumatology and clinical immunology at the University of Maryland School of Medicine, who wrote an accompanying editorial.
He believes the study was flawed because it used glucosamine hydrochloride rather than a different version, glucosamine sulfate. Other studies have shown that the sulfate form of glucosamine can be helpful against pain caused by osteoarthritis, he says.
The sulfate form of glucosamine was not used in the study because it was not possible to find a version that met federal pharmaceutical requirements, says Dr. Clegg.
Dr. Hochberg says he would recommend use of glucosamine sulfate "if people want to take glucosamine on their own or on the recommendation of a health-care provider for pain of osteoarthritis of the knee, not just pain in general or pain at another site."
Glucosamine sulfate "can be taken as a single dose of 1,500 milligrams a day and people can try it for up to 12 weeks," says Dr. Hochberg. "If you didn't notice any clinically important effect by three months, I would stop. Otherwise, I would continue it indefinitely. It is safe, and not associated with any risk of side effects."
Dr. Hochberg differed somewhat with Dr. Clegg on the wisdom of using the two supplements in combination.
"There is little data to support combination therapy," he says. "But most products on the shelf are combination products, and there is no data to suggest an increase in risk with the combination, and no data suggesting that the combination reduces the efficacy of the individual components."
In general, he adds, the use of such supplements for pain relief "is a difficult subject for consumers and difficult for health-care providers."
“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,” says Dr. Stephen E. Straus, NCCAM director.
“It is important to study dietary supplements with well-designed research in order to find out what works and what does not,” he says.
Always consult your physician for more information.
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Osteoarthritis, the most common form of arthritis, is a chronic, degenerative joint disease that affects mostly middle-aged and older adults.
Osteoarthritis is characterized by the breakdown of joint cartilage and adjacent bone in the neck, lower back, knees, hips, and/or fingers.
The disease is also known as degenerative arthritis or degenerative joint disease.
Osteoarthritis can be classified as primary or secondary.
Primary osteoarthritis has an unknown cause, while secondary osteoarthritis is caused by another disease, infection, injury, or deformity.
Osteoarthritis is characterized by the breakdown of cartilage in the joint and adjacent bone.
As the cartilage wears down, the bone ends may thicken, forming bony growths or spurs that interfere with joint movement. In addition, bits of bone and cartilage may float in the joint space and fluid-filled cysts may form in the bone, limiting joint movement.
Several risk factors are associated with osteoarthritis, including the following:
heredity
Slight joint defects or double-jointedness (laxity) and genetic defects may contribute to the development of osteoarthritis.
obesity
Excessive weight can put undue stress on such joints as the knees over time.
injury/overuse
Significant injury to a joint, such as the knee, can later result in osteoarthritis. Injury may also result from repeated overuse or misuse over a period of time.
The most common symptom of osteoarthritis is pain after overuse of a joint or prolonged inactivity of a joint.
The most common joints affected by osteoarthritis include the hips, knees, fingers, feet, and spine.
Symptoms of osteoarthritis usually develop slowly over many years. However each individual may experience symptoms differently.
Symptoms may include:
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joint pain
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joint stiffness, especially after sleeping or inactivity
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limited joint movement as the disease progresses
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grating of joints when moved (in more advanced stages of osteoarthritis) as the cartilage wears away
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back pain
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numbness
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weakness in an arm or leg (in more advanced stages)
Always consult your physician for more information.
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