| High Dose Glucosamine Hydrochloride for Knee Pain Reference: Braham R, Dawson B, Goodman C. The effect of glucosamine supplementation on people experiencing knee pain. Br J Sports Med 2003;37:45-9. Design: Randomized, double-blind, placebo-controlled. Participants: Forty-six male and female subjects (mean age 43 years) suffering from regular knee pain of unspecified origin. Knee pain severity was determined by responses to the Knee Pain Scale (KPS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaires. Study Medication and Dosage: Glucosamine hydrochloride (GH)-2,000 mg q.d. (given once in the morning) Duration: Twelve weeks Outcome Measures: Patients' knee pain was evaluated at baseline and every four weeks throughout the 12-week study by the following questionnaires, clinical and functional exams: KPS and KOOS questionnaires; joint line palpation of both knees (conducted by the investigators); "duck walk" for 3 meters; and a stair climb of 32 steps, repeated up to five times. Subjects were asked to rate their perceived pain after the joint palpation, duck walk and stair climb exams using a 10-point Likert scale (0 = no pain, 10 = excruciating pain). Key Findings: The greatest difference between the two groups was found in the subjective self-reported perception of improvement. Eighty-eight percent of the subjects in the GH group believed that their knee pain had improved by some degree over the 12-week study period while only 17% of subjects in the placebo group reported improvements. By week four, 36% of subjects in the GH group had reported some degree of pain relief and at week eight this had increased to 68%. Sixteen percent of subjects in the GH group showed an increase in distance covered during the duck walk, while there was no change in the distance covered for any subjects in the placebo group. Subjects in the GH group reported less pain after the duck walk than placebo group, while both groups' pain ratings after this test improved over the 12-week period. The GH group had lower average pain ratings after the stair-climbing test than the placebo group. However, both groups showed improvement over the 12 weeks. The mean scores of the KPS for both groups improved over the 12-week study period, but at week eight, the scores in the GH group were significantly lower (indicating increased improvement) than the placebo group (p = 0.004). Both groups showed improvement on the KOOS questionnaire. Significant group differences were observed for pain (p = 0.025) and activities of daily living (p=0.045) where the GH group had higher score (indicative of lower pain) at each assessment. Reports of adverse events were evenly distributed between the two groups and most of the side effects were mild in nature (e.g. gastrointestinal upset, headache). Practice Implications: This small, short-term trial suggests that glucosamine hydrochloride may be useful in the management of chronic knee pain. It should be noted that the daily dose used in this trial is 500 mg higher than that used in the majority of successful trials with glucosamine for osteoarthritis (1,500 mg/day). It is also interesting to note that the entire 2,000 mg dose was taken in the morning. This is further support of the findings of two 3-year trials of glucosamine sulfate for osteoarthritis that found similar results using a once daily dose of 1,500 mg. The rather diverse patient population used in this trial (27 patients had some previous evidence of cartilage damage) and the absence of radiological measures limit the findings. However, the trial does set the stage for a longer clinical trial with a more homogenous patient population and future dose-response studies to see if higher doses of glucosamine may give greater pain relief. Whether it places glucosamine hydrochloride back in the running as an efficacious alternative to glucosamine sulfate, will have to wait for the results of future clinical trials. |
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