Osteoarthritis, the “wear-and-tear” type of arthritis, affects a great many of us as we grow older. Knee pain is a common symptom. The diet supplements glucosamine and chondroitin have been proposed as a more “natural” treatment than pharmaceuticals, and they are components of a number of proprietary “joint health” formulations like Osteo Bi-Flex. The GAIT study (Glucosamine/Chondroitin Arthritis Intervention Trial), compared glucosamine, chondroitin, a combination of the two, and a pharmaceutical (celecoxib) to a placebo in patients with knee pain from osteoarthritis. The only one that worked better than placebo was celecoxib. I wrote about the GAIT trial in 2008. The study was reported in the media as both negative and positive. The positive reports emphasized the subgroup analysis: in one of ten subgroups, patients with moderate to severe pain, the combination of glucosamine and chondroitin outperformed placebo. But in the subgroup of patients with mild to moderate pain, it did not. The authors themselves commented that their study was not powered to draw any conclusions from subgroups and that further studies would be required. (The “power” of a study is a measure of its ability to show an association or relationship between two variables if such a relationship exists.) Now a further study with sufficient power claims to have confirmed the subgroup findings. This may encourage some people to try glucosamine/chondroitin, but I remain skeptical.
Posts Tagged glucosamine
Osteoarthritis is the “wear and tear” kind of arthritis that many of us develop as we get older. Cartilage becomes less resilient with age, collagen can degenerate, and inflammation and new bone outgrowths (osteophytes) can occur. This leads to pain, crepitus (Rice Krispie type crackling noises with movement), swelling and fluid accumulation in the joints (effusion), and can severely limit activity for some patients.
Since knee osteoarthritis is such a ubiquitous annoyance, home remedies and CAM offerings abound. Previously we have covered a number of CAM options on this blog, including glucosamine, acupuncture, and several others. The American Academy of Orthopaedic Surgeons (AAOS) has just issued a 1200 page report evaluating the evidence for various treatments for knee osteoarthritis short of total knee replacement surgery. A 13 page summary is available online. They have done the heavy lifting for us, reviewing all the available scientific studies for evidence of effectiveness. Here’s what the science says: (I’ve highlighted the ones where the evidence is strong.) (more…)
Glucosamine is widely used for osteoarthritis pain. It is not as impossible as homeopathy, but its rationale is improbable. As I explained in a previous post,
Wallace Sampson, one of the other authors of this blog, has pointed out that the amount of glucosamine in the typical supplement dose is on the order of 1/1000th to 1/10,000th of the available glucosamine in the body, most of which is produced by the body itself. He says, “Glucosamine is not an essential nutrient like a vitamin or an essential amino acid, for which small amounts make a large difference. How much difference could that small additional amount make? If glucosamine or chondroitin worked, this would be a medical first and worthy of a Nobel. It probably cannot work.”
Nevertheless, glucosamine (alone or with chondroitin) is widely used, and there are some supporting studies. But they are trumped by a number of well-designed studies that show it works no better than placebo, as well as a study showing that patients who had allegedly responded to glucosamine couldn’t tell the difference when their pills were replaced with placebos. The GAIT trial was a large, well-designed, multicenter study published in The New England Journal of Medicine that showed no effect in knee osteoarthritis. A subsequent study of hip osteoarthritis also showed it worked no better than placebo.
A new study shows that glucosamine works no better than placebo for osteoarthritis pain in the low back. It was published in the JAMA: Effect of Glucosamine on Pain-Related Disability in Patients with Chronic Low Back Pain and Degenerative Lumbar Osteoarthritis: A Randomized Controlled Trial, by Wilkens et al. (more…)
When I recently wrote about glucosamine, I discussed the evidence up through the New England Journal of Medicine study of 2006, which I thought was a pretty definitive study showing that neither glucosamine, chondroitin or a combination of the two was more effective than placebo. Subsequent studies have continued to fuel the controversy. One 2007 study showed that glucosamine sulfate was better than placebo for knee osteoarthritis. Another 2007 study showed that glucosamine HCl and chondroitin, with or without exercise, were no better than placebo for knee osteoarthritis. Sources like the Natural Medicines Comprehensive Database believe the evidence favors glucosamine sulfate but not glucosamine hydrochloride.
A new study was published 19 February 2008 in the prestigious Annals of Internal Medicine. It is arguably the best study to date, and may shed some light on the controversy. Carried out in the Netherlands in a primary care setting, it studied 222 patients with hip osteoarthritis over a 2 year period. Half the patients took glucosamine sulfate 1500 mg a day; half took a placebo. They concluded that glucosamine sulfate was no better than placebo in reducing symptoms and progression of hip osteoarthritis. (more…)
Glucosamine and chondroitin, used separately or together, are among the more popular diet supplements. They are used widely for osteoarthritis, especially of the knee, and have been better studied than most other diet supplements. But do they really work?
The journal of my medical specialty, American Family Physician, recently published an article about the use of dietary supplements in osteoarthritis. They gave a “B” evidence rating to both glucosamine and chondroitin. This means there is inconsistent or limited-quality patient-oriented evidence. They recommended the use of glucosamine sulfate, saying, “Overall, the evidence supports the use of glucosamine sulfate for modestly reducing osteoarthritis symptoms and possibly slowing disease progression.” They did not exactly recommend chondroitin, although they said it “may provide modest benefit for some patients.”