Summary
Alone or in combination, the supplements do not reduce joint pain or limit joint-space narrowing.
Introduction
Randomized trials on the effectiveness of glucosamine and chondroitin for osteoarthritis (OA) have yielded mixed results; the largest trial showed no benefit for these agents, used alone or in combination for knee OA (JW Gen Med Mar 15 2006, p. 45, and N Engl J Med 2006; 354:795).
Now, researchers have conducted a meta-analysis (this is a study that analyzes the other studies) of 10 randomized controlled trials in which about 3800 patients (68% women; median age, 62) with osteoarthritis of the hip or knee received glucosamine, chondroitin, both supplements, or placebo; all patients were evaluated for joint pain — and some for radiological progression of disease — during follow-ups that ranged from 1 to 36 months.
On a 10-cm visual analog pain scale, the difference in pain intensity (compared with placebo) was –0.4 cm for glucosamine, –0.3 cm for chondroitin, and –0.5 cm for the combination. These results were of borderline statistical significance, but they did not approach the researchers’ prespecified minimally important clinical difference of 0.9 cm. Six trials contributed data on radiological joint-space narrowing.
Glucosamine, chondroitin, and the combination had no effect on joint-space narrowing. The supplements, either alone or in combination, however, caused no reported adverse effects
The Bottom Line
Glucosamine, chondroitin, and the combination are no better than placebo in attenuating joint pain or limiting joint-space narrowing in patients with hip or knee OA.
Nevertheless, clinicians likely will encounter patients who are interested in, or report benefit from, using these preparations. In these situations, clinicians should inform patients of the results of clinical trials. For patients who remain steadfast in their desire to take glucosamine, chondroitin, or both, clinicians should be open to empirical trials of these preparations — given their apparent safety — as long as the patients are willing to pay for the compounds.
References
- Wandel S et al. Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: Network meta-analysis. BMJ 2010 Sep 16; 341:c4675.
JTM, MD