(Ivanhoe Newswire) -- Patients taking a commonly prescribed class of diabetes medications may be at risk for bone fractures.

Thiazolidinediones are a relatively new and effective class of drugs designed to treat insulin resistance in type 2 diabetes patients. Twenty-one percent of oral medications prescribed in the United States are pioglitazone (Actos) and rosiglitazone (Avandia) -- two drugs in this category. Previous studies have suggested these medications may cause slower bone formation and faster bone loss, but a new study now reveals they may also be linked to fractures.

Researchers in Switzerland looked at 1,020 patients with diabetes who had fractures. For each patient, they had up to four control subjects who had diabetes, were the same age and sex, had the same physician, but did not have fractures. The results showed those currently taking rosiglitazone and pioglitazone were roughly two to three times more likely to have hip and other non-spine fractures than those not taking the drugs. The risk for fractures increased in those who took the drugs for 12 to 18 months and was highest for those taking them for two or more years.