Background  Thiazolidinediones may adversely affect the skeleton owing to decreased bone formation and accelerated bone loss.

Methods  This study examines the association between the use of thiazolidinediones or other oral antidiabetic drugs and the risk of fracture. This nested case-control analysis uses the UK General Practice Research Database, including case patients with fracture aged 30 to 89 years with an incident fracture diagnosis between January 1994 and December 2005 and control subjects who were matched to case patients on age, sex, calendar time, and general practice attended. We assessed the odds ratios (ORs) of having a fracture associated with the use of rosiglitazone maleate, pioglitazone hydrochloride, other oral antidiabetic agents, or insulin.

Results  There were 1020 case patients with an incident low-trauma fracture and 3728 matched controls. After adjustment for age, body mass index, other antidiabetic drugs, comedication, and comorbidities, the ORs for users of 8 or more thiazolidinedione prescriptions (corresponding to approximately 12-18 months of therapy) compared with nonuse was 2.43 (95% confidence interval [CI], 1.49-3.95). Rosiglitazone (OR, 2.38; 95% CI, 1.39-4.09) and pioglitazone (OR, 2.59; 95% CI, 0.96-7.01) were used more frequently by case patients with fracture (predominantly hip and wrist fractures) than by controls. The association was independent of patient age and sex and tended to increase with thiazolidinedione dose. No materially altered relative fracture risk was found in association with the use of other oral antidiabetic drugs.

Conclusion  This analysis provides further evidence of a possible association between long-term use of thiazolidinediones and fractures, particularly of the hip and wrist, in patients with diabetes mellitus.