Initially, it was thought that rosiglitazone, the generic term for the drug that is marketed as Avandia, was serving as a governor to the bone-building process. In other words, as bones evolve in the human body (much like skin), it was originally thought that Avandia somehow contributed towards an inability to effectively regenerate bone lost in the natural regenerative process.

However, this latest conclusion-arrived at quite by accident-reveals that rosiglitazone actually contributes to bones loss over long treatment periods. Rather then prevent bone from regenerating, Avandia contributes to actual bone loss.

The finding leads to “a better understanding of the challenges associated with long-term treatment of patients with Type II diabetes,” according to Ronald M. Evans of the Salk Institute for Biological Studies in La Jolla, Calif., lead author of the report.

Researchers were conducting studies on diabetic mice, when they stumbled upon their surprising conclusion. Their findings offer hope that this aspect of Avandia as a contributor to bone loss could be further studied and isolated and, one day, ‘dialed-out’ of a future generation of drugs dedicated to the treatment of Type 2 Diabetes.

The Howard Hughes Medical Institute, and the National Institutes of Health funded the research. The findings appeared in this week’s online issue of Nature Medicine.

Researchers found that rosiglitazone-Avandia-stimulates the cells that break down bone in the body, for future regeneration. Osteoporosis occurs when the body loses more bone that it has the capacity to regenerate. Osteoporosis is of particular concern to older women, and this latest research suggests that Avandia should not be prescribed to patients with a history of osteoporosis.

Further, for Avandia patients who also suffer from chronic osteoporosis, there is now the possibility of a contributing cause to the bone loss.

It may not just be from aging. Avandia may be helping it along.

SOURCE: Avandia Recall › Avandia now linked to Osteoporosis

New research raises the possibility that long-term treatment with rosiglitazone, as Avandia is also called, could lead to osteoporosis. The diabetes drug is used to improved response to insulin.

While bones seem solid, they constantly are being broken down and rebuilt by the body. Researchers found that in mice, the drug increased the activity of the cells that degrade bones, according to a report in this week’s online issue of Nature Medicine.

Avandia recently was labeled with warnings about the risk of heart failure in some patients. GlaxoSmithKline, which markets the drug, already has acknowledged that a study found a higher risk of fractures among women who take the drug. But this report is the first to attempt to explain the link between the drug and fractures.

The finding “has led to a better understanding of the challenges associated with long-term treatment of patients with Type II diabetes,” said Ronald M. Evans of the Salk Institute for Biological Studies in La Jolla, Calif., lead author of the report.

“It also provides a basis for the development of a ‘next generation’ of drug that can specifically dial out this side effect and a new insight into a previously unrecognized aspect of bone physiology that has important medical consequences,” he said in an interview via e-mail.

Nearly 21 million people in the United States have diabetes. Rosiglitazone is widely used in people with Type II, or adult onset diabetes, the most common form of the disease.

Evans said the discovery was fortuitous. Researchers were looking at different aspects of the diabetic mice and did not realize they would be able to change the bone-removing activity.

The assumption had been that more brittle bones in diabetics were the result of a reduced bone-building activity, not increased bone removal.

“Considering the widespread use of these drugs and the known action in people it is surprising that such a key observation had been missed,” he said.

“The long-term use of rosiglitazone should be cautious in patients with higher risk of fractures such as older women,” he added. Using it in combination with anti-osteoporosis drugs could be beneficial, he said.

The research was funded by the Howard Hughes Medical Institute and the National Institutes of Health.

December 3rd, 2007 by Randolph E. Schmid with Associated Press

SOURCE: Avandia Recall › Diabetes drug may increase bone thinning