Use of sulphonylurea and cancer in type 2 diabetes-The Hong Kong Diabetes Registry

Background: Hyperglycaemia is a risk factor for cancer and some sulphonylureas have anti-oxidant properties. This study examined associations between use of sulphonylureas and cancer. Methods: A consecutive cohort of 6103 Hong Kong Chinese patients with T2DM, free of cancer, was analysed using Cox models. Sulphonylurea usage was defined as use of the drugs at or within 2.5 years before enrolment and/or during follow-up periods. We adjusted for identified risk factors of cancer, use of other drugs, non-linear associations of lipids with cancer and probabilities of use of these drugs at different times and doses where appropriate. Results: During a median of 4.91 years of follow-up, 271 developed cancer. Glibenclamide, gliclazide and glipizide were ever used in 32.5% (n = 1983), 47.8% (n = 2920) and 13.5% (n = 823). After adjustment for covariates, use of gliclazide and glibenclamide was associated with reduced cancer risk in a dose-dependent manner. In addition, there were interactions between metformin and glibenclamide/glipizide use towards lower adjusted cancer risks. Conclusions: In T2DM, use of glibenclamide and gliclazide may be associated with reduced cancer risk. (C) 2010 Elsevier Ireland Ltd. All rights reserved.