Chondroitin sulphate for symptomatic osteoarthritis: critical appraisal of meta-analyses.
Chondroitin sulphate (CS) is an important structural component of cartilage and is approved and regulated as a symptomatic slow-acting drug for osteoarthritis (OA) (SYSADOA) in Europe and some other countries. Although numerous studies have shown the clinical benefits of CS to decrease pain, improve functional disability, reduce non-steroidal anti-inflammatory drug (NSAID) or acetaminophen consumption, and good tolerability with an additional carry-over effect, there are still some concerns regarding its effectiveness in treating OA. To examine the data provided by meta-analyses to clarify the effectiveness of CS as a symptomatic treatment for OA. A MEDLINE database search was conducted for appropriate meta-analyses published between 1997 and 2007. Five meta-analyses that limited their analysis to randomised controlled trials (RCTs) comparing CS with placebo or no-treatment control arms were retrieved. Four meta-analyses showed significant clinical effects of CS compared with placebo for pain and function measures and one demonstrated greater reduction of analgesic co-medication in patients assigned to the active treatment. In one meta-analysis, the 20 trials included in the study showed a high degree of heterogeneity and the conclusion that CS showed minimal symptomatic benefits was based on the analysis of only three trials. One meta-analysis showed that pain relief after CS treatment steadily increased between 4 and 12 weeks of treatment, whereas the time course of pain relief after treatment with NSAIDs decreased. Two meta-analyses reported consistently higher frequencies of side effects in the placebo group than in patients treated with CS. Data provided by these meta-analyses indicate that CS has a slight to moderate efficacy in the symptomatic treatment of OA, with an excellent safety profile.