A class of popular diabetes drugs has been found to be associated with an increased risk of fractures of the hip and wrist in insulin-resistant patients.  The class of drug, insulin-sensitizing thiazolidinediones, makes up about 21% of the oral medications taken for diabetes in the United States and 5% in Europe.

Pioglitazone and rosiglitazone, the two specific drugs in question, are thought to cause slow bone formation and accelerated bone loss, resulting in fractures.  Researchers in Switzerland analyzed the medical records of diabetic British patients from 1994 to 2005.  They matched groups of four diabetics, all without fractures but of the same age, gender, and who were being treated by the same physician.  The research team, led by Christian Meier, MD, of the University Hospital Basel, worked with 3,728 matched groups of four.

What the researchers found was somewhat alarming.  Diabetic patients taking either pioglitazone or rosiglitazone had double and triple the chances of hip fractures and other fractures that did not involve the spine.  The risk increased after taking the medications for 12 to 18 months and was highest when patients took the drugs for two or more years.

Other drugs routinely prescribed for diabetes were analyzed in the study but no association with bone fractures was revealed.

The April 28 issue of Archives of Internal Medicine carries the full details of the Swiss study.