Abstract
Glucosamine is an aminosaccharide with a molecular weight of 179.2 and the source of various aminosugars that make up the extracelluar matrix and glycoproteins. It also has biological effects on chondrocytes and other cells; for example, glucosamine is known to suppress the production of PGE 2 and MMPs from chondrocytes. Glucosamine has been used to treat osteoarthritis (OA) since the 1960s, however, clinical trials have reported inconsistent results. According to a recent meta-analysis, effect size of glucosamine was decreased to 0.35. The study showed the following two points; 1) only products of a specific company are effective and 2) glucosamine hydrochloride was ineffective. Regarding industry bias, controversy exists as to whether well-designed clinical studies supported by pharmaceutical companies thus show robust results on efficacy. Both glucosamine hydrochloride and its sulfate dissociate are absorbed as glucosamine in the oral mucosa. Careful analysis of clinical trials using glucosamine hydrochloride do not inevitably show that it is ineffective. Chondroitin sulfate is a high molecular weight compound composed of galactosamine and glucuronic acid. The meta-analysis showed negative results, partly because the quality of products is heterogeneous. To elucidate the efficacy of these products, investigation into the diagnosis and evaluation of OA is important.
