Benefits of chondroitin in knee osteoarthritis

 Researchers from the University of Paris Descartes in France assessed the long-term effects of chondroitins 4 and 6 sulfate on the symptoms and radiographic progression of knee osteoarthritis (OA).

Chondroitin sulfate is an important structural component of cartilage and provides resistance to compression. The term “chondroitins 4 and 6 sulfate” refers to where on the molecule the sulfate is attached — site 4 or 6.

Now, the details.

• 622 patients with knee OA were randomly assigned to 800 mg chondroitin or placebo once daily for 2 years.
• X-rays of the target knee were taken at 12, 18, and 24 months.
• Changes in the minimum joint space width of the medial compartment of the tibiofemoral joint was assessed.
• The primary outcome was the loss in minimum joint space width over 2 years.
• The patients and researchers were not aware of the treatment given — double-blind.

And, the results.

• The chondroitin group showed an insignificant difference between minimum joint space width measurements at 0 and 24 months.

Minimum joint space width

• At 0 and 24 months the width decreased significantly with placebo.
• The difference between the placebo and chondroitin groups was significant.

Average joint space width

• Remained constant over 2 years with chondroitin, but decreased with placebo.
• The difference between the placebo and chondroitin was significant.

The bottom line?
The authors concluded, “Chondroitin sulfate is statistically superior to placebo for minimum joint space width stabilization and mean joint space width stabilization.”

“Chondroitin sulfate qualifies as a disease-modifying osteoarthritis drug (DMOAD) and is especially active in specific patient populations, including obese patients, patients younger than 60 years, and patients with mild-to-moderate osteoarthritis.”

Chondroitin has some structure-modifying effect. And these results support an earlier study from 2005.

However, the question raised in 2005 remains relevant today. How does taking chondroitin or the changes seen on X-ray relate to pain control?

A review in American Family Physician summarized here (you’ll have to pay to read it here) concluded there was “no benefit to minimal benefit of oral chondroitin in reducing osteoarthritis pain.”

2/2/09 20:41 JR