This study tested chondroitin sulfate 800 mg/day (CS) pharmaceutical-grade in the management of symptomatic knee osteoarthritis. It was designed as a prospective, randomised, 6-month, 3-arm, double-blind, double-dummy, placebo and celecoxib (200 mg/day)-controlled trial. The primary endpoints were changes in pain on a Visual Analogue Scale (VAS) and in the Lequesne Index (LI). Minimal-Clinically Important Improvement (MCII), Patient-Acceptable Symptoms State (PASS) were used as secondary endpoints.
A total of 604 patients, diagnosed according to American College of Rheumalogy (ACR) criteria, were recruited in five European countries and followed for 182 days. CS and celecoxib showed a greater significant reduction in pain and LI than placebo. In the intention-to-treat (ITT) population, pain reduction in VAS at day 182 in the CS group (−42.6 mm) and in celecoxib group (−39.5 mm) was significantly greater than the placebo group (−33.3 mm) (p=0.001 for CS and p=0.009 for celecoxib). No difference observed between CS and celecoxib. Similar trend for the LI, as reduction in this metric in the CS group (−4.7) and celecoxib group (−4.6) was significantly greater than the placebo group (−3.7) (p=0.023 for CS and p=0.015 for celecoxib). Again, no difference was observed between CS and celecoxib. Both secondary endpoints (MCII and PASS) at day 182 improved significantly in the CS and celecoxib groups. All treatments demonstrated excellent safety profiles.
The authors concluded that a 800 mg/day pharmaceutical-grade CS is superior to placebo and similar to celecoxib in reducing pain and improving function over 6 months in symptomatic knee osteoarthritis (OA) patients. This formulation of CS should be considered a first-line treatment in the medical management of knee OA.
In my view, this is a good study with clear and useful results: CS seems to be efficacious and safe. Another recent study confirmed the superiority of CS over celecoxib at reducing cartilage volume loss in knee OA patients.
The current Cochrane review does not yet account for the new data; it concluded cautiously positive: A review of randomized trials of mostly low quality reveals that chondroitin (alone or in combination with glucosamine) was better than placebo in improving pain in participants with osteoarthritis in short-term studies. The benefit was small to moderate with an 8 point greater improvement in pain (range 0 to 100) and a 2 point greater improvement in Lequesne’s index (range 0 to 24), both seeming clinically meaningful. These differences persisted in some sensitivity analyses and not others. Chondroitin had a lower risk of serious adverse events compared with control. More high-quality studies are needed to explore the role of chondroitin in the treatment of osteoarthritis. The combination of some efficacy and low risk associated with chondroitin may explain its popularity among patients as an over-the-counter supplement.
The call for more high quality trials was justified but has now been answered. In my view, CS can be considered an evidence-based option in the management of OA.