Glucosamine sulfate reduces osteoarthritis progression in postmenopausal women with knee osteoarthritis: evidence from two 3-year studies

Objective: To investigate the effect of glucosaminesulfate on long-term symptoms and structure progression in postmenopausal women with knee osteoarthritis (OA). Design: This study consisted of a preplanned combination of two three-year, randomized, placebo-controlled, prospective, independent studiesevaluating the effect of glucosaminesulfate on symptoms and structure modification in OA and post-hoc analysisof the results obtained in postmenopausal women with knee OA. Minimal joint spacewidth was assessed at baseline and after 3 years from standing anteroposterior knee radiographs. Symptoms were scored by the algofunctional WOMACindex at baseline and after 3 years. All primary statistical analyses were performed in intention-to-treat, comparing joint spacewidth and WOMACchanges between groups by ANOVA. Results: Of 414 participants randomized in the two studies, 319 were postmenopausal women. At baseline, glucosaminesulfate and placebo groups were comparable for demographic and disease characteristics, both in the general population and in the postmenopausal women subset. After 3 years, postmenopausal participants in the glucosaminesulfate group showed no joint space narrowing[ joint spacechange of +0.003 mm (95% CI, �0.09 to 0.11)], whereas participants in the placebo group experienced a narrowing of �0.33 mm (95% CI, �0.44 to �0.22; P < 0.0001 between the two groups). Percent changes after 3 years in the WOMACindex showed an improvement in the glucosaminesulfate group [�14.1% (95%, �22.2 to �5.9)] and a trend for worsening in the placebo group (5.4% (95% CI, �4.9 to 15.7) (P = 0.003 between the two groups). Conclusion: This analysis, focusing on a large cohort of postmenopausal women, demonstrated for the first time that a pharmacological intervention for OA has a disease-modifying effect in this particular population, the most frequently affected by knee OA.