To examine whether exposure to pioglitazone use is associated with increased incidence of bladder cancer in patients with type 2 diabetes mellitus.

A cohort study was done in the General Practice Research Database (GPRD) between 2001 and 2010. 207,714 patients aged ≥40 years with type 2 diabetes were studied (23,548 exposed to pioglitazone and 184,166 exposed to other antidiabetic medications but not pioglitazone). The association between pioglitazone and risk of bladder cancer was assessed by a Cox regression model. A propensity score matched analysis was done in a group of patients without missing baseline characteristics data.

66 and 803 new cases of bladder cancer occurred in the pioglitazone and other group respectively (rates of 80.2 (95%CI 60.8-99.5) and 81.8 (95%CI 76.2-87.5) per 100,000 person-years respectively). Pioglitazone did not increase the risk of bladder cancer significantly compared with other antidiabetic drugs treatment group, (adjusted hazard ratio (HR), 1.16, 95%CI 0.83-1.62). In a matched propensity score analysis in which both groups had similar baseline characteristics (17,249 patients in each group), the adjusted HR was 1.22 (95% CI 0.80-1.84).

The results suggest that pioglitazone may not be significantly associated with an increased risk of bladder cancer in patients with type 2 diabetes. © 2012 The Authors. British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

© 2012 The Authors. British Journal of Clinical Pharmacology © 2012 The British Pharmacological Society.

PMID: 22574756 [PubMed - as supplied by publisher] Source: National Library of Medicine.