Assessment Of Glucosamine And Chondroitin Trials For Osteoarthritis

Dateline: March 25, 2000

37 Studies Analyzed

The March 15, 2000 issue of the Journal of the American Medical Association included a report on a study by Timothy E. McAlindon, M.D. and colleagues from Boston University School of Medicine. After combing through more than three decades of scientific literature, the Boston researchers found 37 studies of glucosamine and chondroitin sulfate for the treatment of osteoarthritis.

Of the 37 studies, 15 which were published between 1980 and 1998 were double-blind, randomized, placebo-controlled trials which lasted four weeks or more. Of the 15 trials:

• 6 involved glucosamine
• 9 involved chondroitin

Flaws In Methodology

The research team from Boston University School of Medicine analyzed and evaluated each of the clinical trials and then combined the data from the different trials. Amidst the analyzed studies, flaws in methodology and biases were discovered, some of which inflated the beneficial aspects of glucosamine and chondroitin.

Based on a calculation the researchers determined the overall effect for both glucosamine and chondroitin with 0.2 being indicative of a small effect, 0.5 corresponding to a moderate effect, and 0.8 pointing to a large effect. The researchers determined that the effect was:

• 0.44 for glucosamine
• 0.78 for chondroitin sulfate

Reportedly, these values were lower when only the largest and highest quality trials were evaluated.

During the past several years, skeptics of glucosamine and chondroitin have discouraged patients from trying the dietary supplements, primarily because of the lack of regulation over the manufacturing and marketing of supplements in the United States and also because of insufficient scientific studies. All along patients have been urged not to stop ongoing medical treatments in order to try the supplements and have been advised to consult their doctors if contemplating a trial of glucosamine or chondroitin.

More Studies Needed

Clearly, more studies are needed which will provide evidence of the effectiveness or ineffectiveness of glucosamine and chondroitin. Conclusions about glucosamine and chondroitin as a treatment for osteoarthritis are yet to be drawn.

The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) and the National Center for Complementary and Alternative Medicine (NCCAM), both parts of the National Institutes of Health (NIH), have launched the largest study of glucosamine and chondroitin to date. The NIH Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT).

Editor note: Long awaited results from GAIT (Glucosamine/Chondroitin Arthritis Intervention Trial) and GUIDE (Glucosamine Unum In Die Efficacy) were presented at the 2005 ACR meeting.

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