One commonly prescribed diabetes medication is contributing to higher rates of bone fractures among elderly women, a new report finds.

The drug thiazolidinedione (TZD) is commonly used to treat insulin resistance in patients with type 2 diabetes, according to the study from the Center for Health Services Research and Department of Internal Medicine at Henry Ford Hospital. To determine if there was a the link between TZD and bone fractures, researchers studied 19,070 men and women, 4,511 of whom had a prescription for the drug. After one year, researchers began to notice a trend among older women.

There was no increased risk of fractures for men who participated in the study, but among women aged 65 and older there was a 50% increase in the risk of fracture after one year on TZD, the research shows. The location of the fractures was unusual as well, researchers noted. While most fractures among the elderly occur in the hip or vertebra, TZD was associated with increased fractures in the upper extremities and distal lower extremities. The report appears in the February edition of The Journal of Clinical Endocrinology & Metabolism.