Glucosamine is increasingly used to treat osteoarthritis. However, animal studies have shown that high glucosamine levels can raise blood glucose levels, explain the authors of an article in the Archives of Internal Medicine.

In the first clinical trial of its kind, Dr. Daren Scroggie from Wilford Hall Medical Center at Lackland Air Force Base, Texas, and associates studied the effects of glucosamine supplementation on glucose control in 34 mostly elderly patients with type 2 diabetes.

Over time, glucose control changed very little, the researchers report, whether or not the subjects were taking glucosamine.

Only one patient withdrew from the study due to a possible side effect from glucosamine (excessive flatulence), the report indicates, and medical therapy did not change during the study.

The typical oral doses of glucosamine are around 20 milligrams per kilogram of body weight per day, the team explains. By comparison, the equivalent doses used in animal studies were much higher, ranging from about 3000 milligrams up to 435,000 milligrams.

"Since patients with diabetes are at risk for toxic effects from some of the current treatments for osteoarthritis (NSAIDs in particular)," the authors conclude, "glucosamine may provide a safe alternative treatment for these patients."

SOURCE: Archives of Internal Medicine, July 13, 2003.