Chondroitins could be disease-modifying agents for knee osteoarthritis

Long-term administration of chondroitins 4 and 6 sulfate (CS) can prevent joint structure degradation in patients with knee osteoarthritis (OA). Reduced loss of joint-space width (JSW) might be predictive of better OA outcomes.

Kahan and coworkers assigned a cohort of 622 patients to placebo or 800 mg of CS, once daily for 2 years. Digital image analysis was used to assess the minimum JSW of the medial compartment of the tibiofemoral joint. Symptoms were assessed using the visual analog scale (VAS) and the Western Ontario and McMaster Universities OA Index. Patients also reported their use of acetaminophen and NSAIDs.

Compared with placebo, CS significantly blunted the loss of JSW. The percentage of patients with radiographic progression of disease, as evidenced by a JSW decrease of 0.25 mm or more, was 28% in the CS group versus 41% in the placebo group. Discomfort and pain resolved significantly faster in the CS group. The percentage of patients who showed at least a 40% or 60% reduction on the VAS at 6 months was greater in the CS group (53% vs 45%).

The authors surmised that the long-term structural benefits of CS might relate to its effects on cartilage metabolism.