The Effect of Oral Glucosamine Sulfate on Insulin Sensitivity in Human Subjects

As glucosamine is presently in wide use due to its purported beneficial effects in patients with osteoarthritis, it seemed important to consider its possible adverse effects on glucose metabolism. Many subjects who take glucosamine for osteoarthritis are obese, insulin resistant, diabetic, or at risk for the development of diabetes, and it is established that glucosamine induces insulin resistance in rats and mice. Hypotheses suggest that glucosamine causes insulin resistance by directly entering the hexosamine biosynthetic pathway. It has been proposed that this provides a model for glucotoxicity-induced defects in insulin action and secretion (1), since, under hyperglycemic conditions, a larger amount of glucose flux is metabolized through the hexosamine pathway. Therefore, we undertook this study to determine if glucosamine, taken at recommended doses for the treatment of osteoarthritis, had any detrimental …