Study Question: Is either glucosamine or chondroitin effective in decreasing the symptoms of osteoarthritis?

Setting: Outpatient (any)

Study Design: Meta-analysis (randomized controlled trials)

Synopsis: The authors of this meta-analysis searched for all randomized, placebo-controlled, clinical trials of glucosamine or chondroitin for the treatment of hip or knee arthritis. They thoroughly searched several databases and citation lists of retrieved articles, and contacted pharmaceutical companies. Of the 500 studies initially identified, 15 studies involving 1,775 patients met their inclusion criteria.

Glucosamine and chondroitin both produced a pronounced effect on symptoms as identified by a visual analog scale (effect size: 0.49; 95 percent confidence interval [CI], 0.31 to 0.67) and by the Western Ontario McMaster University Osteoarthritis Index (effect size: 0.3; 95 percent CI, 0.11 to 0.49), a commonly used measure of pain and physical function. Joint mobility also improved markedly (effect size: 0.59; 95 percent CI, 0.25 to 0.92), with one person responding for every five patients treated (number needed to treat = 4.9). The rates of adverse effects were similar in the treatment and placebo groups.

Bottom Line: Glucosamine and chondroitin produce a similar significant effect on symptoms of osteoarthritis, improve joint mobility for one in five patients, and also may slow joint-space narrowing. Onset of action is several weeks. (Level of Evidence: 1a)