The Use of Glucosamine in Osteoarthritis

Osteoarthritis (OA), the most widespread type of arthritis, is a degenerative disease of the joints. It is mostly due to"wear-and-tear" disease involving degeneration of joint cartilage and formation of bony spurs within various joints. Trauma to the joints, repetitive occupational usage, and obesity are risk factors. It is common over the age of 60 and the main goal of treatment is to relieve pain.

In recent years, glucosamine and chondroitin have been widely promoted as a treatment for OA. Glucosamine, an amino sugar, is thought to promote the formation and repair of cartilage. Chondroitin, a carbohydrate, is a cartilage component that is thought to promote water retention and elasticity and to inhibit the enzymes that break down cartilage. Both compounds are manufactured by the body.

Research Findings

Laboratory studies suggest that glucosamine may stimulate production of cartilage-building proteins. Other research suggests that chondroitin may inhibit production of cartilage-destroying enzymes and fight inflammation too. Glucosamine supplements are derived from shellfish shells; chondroitin supplements are generally made from cow cartilage. Human studies have shown that either one may relieve arthritis pain and stiffness with fewer side effects than conventional arthritis drugs. Some published studies comparing glucosamine or chondroitin to various standard medications have found that the drugs worked faster than the supplements. But they also found that several months after treatment ended, the analgesic effect of the supplements remained stronger.

In March 2000, a study in the Journal of the American Medical Association concluded:

Trials of glucosamine and chondroitin preparations for OA symptoms demonstrate moderate to large effects, but quality issues and likely publication bias suggest that these effects are exaggerated. Nevertheless, some degree of efficacy appears probable for these preparations [1].

In 2001, the Lancet published the results of a three-year double-blind clinical trial involving 212 people with osteoarthritis who took either glucosamine or a placebo. The researchers found that symptoms improved 20% to 25% in the glucosamine group but worsened slightly in the placebo group. The x-ray examinations showed that serious narrowing of the knee-joint space -- a sign of progression of the disease -- occurred in only half as many patients taking glucosamine as in those receiving the placebo [3]. As for chondroitin, a recent analysis of the combined results of seven randomized, controlled trials indicated that the supplement may reduce osteoarthritis symptoms and improve function by an average of some 50%, although the studies had flaws that may exaggerate the benefits.

Safety Considerations

No study so far has found any serious side effects from either glucosamine or chondroitin. The most common side effects are increased flatulence and softened stools. Patients with diabetes should monitor their blood-sugar level particularly carefully when using the supplement. There have been no reports of allergic reactions to glucosamine. But since it's made from shellfish shells, people who are allergic to seafood should use it cautiously, watching for reactions, or avoid it entirely. As for chondroitin, it can cause bleeding in people who have a bleeding disorder or take a blood-thinning drug (warfarin)

It may take two months to produce any significant improvement. If you see no effect by then, and have taken the full dose of 1.5g per day it's probably best to try a different approach.

A clinical trial that should add considerably to medical knowledge about glucosamine and chondroitin has been funded and is now recruiting patients. It will be a 24-week, placebo-controlled, double-blind, study that will evaluate the effect on osteoarthritic knee pain of glucosamine hydrochloride, chondroitin, a combination of the two, and celicoxib among 1588 participants at 13 centres throughout the country over a 27-month period [5]. The estimated completion date in March 2005.

Glucosamine products

Currently glucosamine and chondroitin products are regarded as food supplements and not available on NHS prescription

90 capsules for 1 months supply are available for £19.99 from the Dispensary

References:

  1. McAlindon TE and others. Glucosamine and chondroitin for treatment of osteoarthritis: A systematic quality assessment and meta-analysis JAMA 283:1469-1475, 2000. [ Full-text version is accessible online for JAMA subscribers.]
  2. Tanveer E, Anastassiades TP. Glucosamine and chondroitin for treating symptoms of osteoarthritis: Evidence is widely touted but incomplete. JAMA 283:1483-1484, 2000. [ Full-text version is accessible online for JAMA subscribers.]
  3. Reginster JY and others. Long-term effects of glucosamine sulfate on osteoarthritis progression: a randomized, placebo-controlled trial . Lancet 357:251-256, 2001.
  4. Study of the efficacy of glucosamine and glucosamine/chondroitin sulfate in knee osteoarthritis . NIH Web site, accessed Jan 22, 2002
  5. Bandolier - Glucosamine and arthritis 2001