Comparison of glucosamine‐containing dietary supplements on knee osteoarthritis symptoms

A preliminary, randomized, double‐blind, placebo‐controlled, parallel‐group clinical study compared efficacy and tolerability of dietary supplements on 107 total subjects with mild to moderate osteoarthritis (OA) of the knee over 8 weeks. Average age was 57 ± 10 years. 18 subjects per group took either placebo (maltodextrin) (Group 1), glucosamine HCl (1500 mg) (Group 2), glucosamine HCl (1500 mg) & chondroitin sulfate (1200 mg) (Group 3), glucosamine HCl (1500 mg) & chondroitin (1200 mg) & sodium hyaluronate (3.3 mg) (Group 4), glucosamine HCl (1500 mg) & a proprietary herbal extract (250 mg) & sodium hyaluronate (3.3 mg) (Group 5), or an experimental formula (Group 6). Acetaminophen was used as rescue medication. WOMAC, SF‐36v2, Brief Pain Inventory (BPI), and Pain Relief Diary (PRD) outcomes were measured at 0, 1, 2, 4, and 8 weeks. Comparisons of Intention‐To‐Treat data across all groups were performed using one‐way factorial ANOVA. There were no significant differences among groups at baseline. Incidence of side effects among groups was not different. All of the groups reported improvements in the subjects’ perceptions of their condition (pain, quality of life, etc.). All groups showed similar efficacy, except for the following: Group 3 was less effective in relieving pain than the other groups; and Group 5 was rated best by the subjects in decreasing joint pain and muscle aches, and showed the greatest amount of rapid‐onset improvement in physical functioning. Supported by Schiff Nutrition International, Inc.