Avandia Could Weaken Bones

According to a new study conducted in mice, Avandia(rosiglitazone), a drug used by millions of diabetes patients, may contribute to bone loss.

Experts fear that, over the long term, Avandia may speed osteoporosis, the thinning of the bones that can lead to dangerous and even fatal fractures.

Earlier this year, Avandia and four other diabetes drugs from the same class were given a “black box” warning by the U.S. Food and Drug Administration. That warning advises users of an increased risk of heart failure while on the drug. The black box message is the FDA’s strongest label warning.With an estimated 3.5 million or more U.S. patients taking Avandia, the public health impact from the point of view of both heart failure and bone degradation could be substantial, experts say.

Avandia affects a key cellular protein called the peroxisome proliferator-activated receptor (PPAR-gamma). In their study, the California team discovered that, in mice, activating this receptor also stimulates the production of osteoclasts, cells whose key function is to degrade bone.

Proper bone health is maintained by a balance between osteoclasts and osteoblasts, the cells that build bone up.

If either side is out of whack, so to speak, bones become thinner, more fragile and prone to fracture.