STUDY SUMMARY
Chondroitin + glucosamine not better than placebo
This multicenter, randomized, double-blind, placebo-controlled trial was conducted in nine rheumatology referral centers and one orthopedic center in Spain. The trial evaluated the efficacy of chondroitin sulfate (1,200 mg) plus glucosamine sulfate (1,500 mg) (CS/GS) compared with placebo in 164 patients with Grade 2 or 3 knee OA and moderate-to-severe knee pain. OA grade was ascertained using the Kellgren-Lawrence scale, corresponding to osteophytes and either possible (Grade 2) or definite (Grade 3) joint space narrowing. Knee pain severity was defined by a self-reported global pain score of 40 to 80 mm on a 100-mm visual analog scale (VAS).
No significant difference was noted in group characteristics; average age in the CS/GS group was 67 and in the placebo group, 65. Exclusion criteria included BMI ≥ 35, concurrent arthritic conditions, and any coexisting chronic disease that would prevent successful completion of the trial.1
The primary endpoint was mean reduction in global pain score on a 0- to 100-mm VAS at six months. Secondary outcomes included mean reduction in total and subscale scores in pain and function on the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index (0–100-mm VAS for each) and the use of rescue medication.
Baseline global pain scores were 62 mm in both groups. Acetaminophen, up to 3 g/d, was the only allowed rescue medication. Clinic visits occurred at 4, 12, and 24 weeks. A statistically significant difference between groups was defined as P < .03.1
Results. In the intention-to-treat analysis at six months, patients in the placebo group had a greater reduction in pain than the CS/GC group (–20 mm vs –12 mm; P = .029). No other difference was noted between the placebo and CS/GS groups in the total or subscales of the WOMAC index, and no difference was noted in use of acetaminophen. More patients in the placebo group had at least a 50% improvement in pain or function compared with the CS/GS group (47.4% vs 27.5%; P = .01).
Continue to: In the CS/GS group...