Glucosamine sulphate: an umbrella review of health outcomes

BACKGROUND & AIMS: Glucosamine sulphate (GS) can be used as background therapy in people affected by knee osteoarthritis (OA). The knowledge regarding the efficacy and safety of GS is of importance since its use worldwide is increasing. Therefore, the present study aimed to map and grade the diverse health outcomes associated with GS using an umbrella review approach. METHODS: Medline, Cinhal and Embase databases were searched until 01st April 2020. An umbrella review of systematic reviews and meta-analyses of randomized controlled trials (RCTs) was carried out. The evidence from RCTs was graded using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) tool. RESULTS: From 140 articles returned, 11 systematic reviews, for a total of 21 outcomes (37 RCTs; 3,949 participants; almost all using 1,500 mg/day), were included. No systematic reviews/meta-analyses of observational studies were included. Regarding the findings of the meta-analyses, 9/17 outcomes were statistically significant, indicating that GS is more effective than placebo. A high certainty of evidence, as assessed by the GRADE, supported the use of GS (vs. placebo), in improving the Lequesne index, joint space width change, joint space width change after 3 years of follow-up, joint space narrowing and OA progression. No difference in terms of adverse effects was found between GS and placebo. In systematic reviews, GS was associated with a better glucose profile and a better physical function performance than placebo. CONCLUSIONS: GS, when used as prescription drug (i.e. crystalline glucosamine sulfate) at 1,500mg daily dosage, can positively affect the cartilage structure, reduce pain, improve function and glucose metabolism in people with knee OA, without having a greater incidence of adverse effects than placebo.