Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis

Wandel S, Jüni P, Tendal B, et al. · BMJ

Against placebo the overall pain difference on a 10 cm scale was -0.4 cm (95% credible interval -0.7 to -0.1) for glucosamine, -0.3 cm (-0.7 to 0.0) for chondroitin and -0.5 cm (-0.9 to 0.0) for the combination: distinct from zero for the single agents, and below the prespecified 0.9 cm minimal clinically important difference for all three. Joint-space differences were -0.2 mm (-0.3 to 0.0), -0.1 mm (-0.3 to 0.1) and 0.0 mm (-0.2 to 0.2). Industry-independent trials showed effects 0.5 cm (0.1 to 0.9) smaller than sponsored ones (P=0.02 for interaction), and adverse-event and withdrawal odds ratios sat near 1.

Population

10 large randomised trials (an average of at least 100 patients per arm) in knee or hip osteoarthritis, seven of them funded by manufacturers

Intervention

Glucosamine, chondroitin, or their combination (any formulation)

Comparator

Placebo

Limitations

Restricted to trials with an average of at least 100 patients per arm, which excludes the small positive studies by design. Stratified analyses found no interaction by glucosamine salt (P>=0.20 for interaction), and the authors state that the lack of a clinically relevant effect holds for glucosamine sulphate. Funded by the Swiss National Science Foundation; no author affiliated with or funded by a manufacturer of the agents evaluated.