Quimica

RESEARCH
Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee: network meta-analysis
¨ Simon Wandel, research fellow,1,2 Peter Juni, professor and head of division,1,2 Britta Tendal, research fellow,3 1,2 ¨ Eveline Nuesch, research fellow, Peter M Villiger, director,4 Nicky J Welton, senior research fellow,5 Stephan Reichenbach, senior researchfellow,1,4 Sven Trelle, senior research fellow1,2
1 Institute of Social and Preventive Medicine, University of Bern, Switzerland 2 CTU Bern, Bern University Hospital, Switzerland 3 Nordic Cochrane Centre, Righospitalet, Copenhagen, Denmark 4 Department of Rheumatology, Clinical Immunology, and Allergology, Bern University Hospital, Switzerland 5 Academic Unit of Primary Health Care, Department ofCommunity Based Medicine, University of Bristol, Bristol, United Kingdom Correspondence to: P Jüni, Institute of Social and Preventive Medicine, University of Bern, Switzerland juni@ispm.unibe.ch

Cite this as: BMJ 2010;341:c4675 doi:10.1136/bmj.c4675

ABSTRACT Objective To determine the effect of glucosamine, chondroitin, or the two in combination on joint pain and on radiological progression ofdisease in osteoarthritis of the hip or knee. Design Network meta-analysis. Direct comparisons within trials were combined with indirect evidence from other trials by using a Bayesian model that allowed the synthesis of multiple time points. Main outcome measure Pain intensity. Secondary outcome was change in minimal width of joint space. The minimal clinically important difference betweenpreparations and placebo was prespecified at −0.9 cm on a 10 cm visual analogue scale. Data sources Electronic databases and conference proceedings from inception to June 2009, expert contact, relevant websites. Eligibility criteria for selecting studies Large scale randomised controlled trials in more than 200 patients with osteoarthritis of the knee or hip that compared glucosamine, chondroitin, or theircombination with placebo or head to head. Results 10 trials in 3803 patients were included. On a 10 cm visual analogue scale the overall difference in pain intensity compared with placebo was −0.4 cm (95% credible interval −0.7 to −0.1 cm) for glucosamine, −0.3 cm (−0.7 to 0.0 cm) for chondroitin, and −0.5 cm (−0.9 to 0.0 cm) for the combination. For none of the estimates did the 95% credibleintervals cross the boundary of the minimal clinically important difference. Industry independent trials showed smaller effects than commercially funded trials (P=0.02 for interaction). The differences in changes in minimal width of joint space were all minute, with 95% credible intervals overlapping zero. Conclusions Compared with placebo, glucosamine, chondroitin, and their combination do not reducejoint pain or have an impact on narrowing of joint space. Health authorities and health insurers should not cover the costs of these preparations, and new prescriptions to patients who have not received treatment should be discouraged. INTRODUCTION Osteoarthritis of the hip or knee is a chronic condition mostly treated with analgesics and non-steroidal anti-

inflammatory drugs, but these drugscan cause serious gastrointestinal and cardiovascular adverse events, especially with long term use.1 2 Disease modifying agents that not only reduce joint pain but also slow the progression of the condition would be desirable. Throughout the world for the past 10 years, the cartilage constituents chondroitin and glucosamine have been increasingly recommended in guidelines, prescribed by generalpractitioners and rheumatologists, and used by patients as over the counter medications to modify the clinical and radiological course of the condition.3 Global sales of glucosamine supplements reached almost $2bn (£1.3bn, €0.8bn) in 2008, which represents an increase of about 60% compared with 2003, with a forecasted continued growth through 2013 reaching $2.3bn.4 The oral administration of...