Analysis of data from a controlled trial of different antidiabetic drugs found that the risk of bone fractures with rosiglitazone was about twice that with metformin or glibenclamide (glyburide).
The findings were published early online in Diabetes Care.
Patients with type 2 diabetes have an increased risk of fractures: this may be despite normal bone density and is thought to be at least partly due to increased disability and risk of falls.
There is evidence that rosiglitazone and pioglitazone are associated with an increased risk of fractures, and the authors of this paper used data from a randomised controlled trial, ADOPT, to investigate the link further for rosiglitazone.
ADOPT compared rosiglitazone, metformin, and glibenclamide as initial drug therapy for adult patients with type 2 diabetes, primary outcome being blood glucose control, with median treatment duration being 4.0 years for rosiglitazone and metformin, and 3.3 years for glibenclamide.
Data on adverse events, including fractures, were collected as part of the trial protocol, and this paper reports a post hoc analysis of the fracture data by drug.
The authors conclude that long-term treatment with rosiglitazone in type 2 diabetes is associated with approximately double the risk of fractures compared to the other therapies.
The increase occurred in both pre-menopausal and post-menopausal women, although the incidence was much higher in post-menopausal women.
There was no apparent relationship with falls or accidental injury, and no specific risk factors could be identified.