Are sulphonylureas all the same? A cohort study on cardiovascular and cancer‐related mortality

Abstract

Background Aim of the present study is the comparison of all‐cause, cardiovascular and non‐cardiovascular mortality, and cardiac morbidity, between patients treated with glibenclamide and gliclazide. Methods A retrospective observational cohort study was performed on a consecutive series of 568 outpatients (282 women, 286 men) with type 2 diabetes treated with either glibenclamide (n = 378) or gliclazide (n = 190). Information on all‐cause mortality and on causes of death up to 31 December 2004 was obtained by the City of Florence Registry Office. Non‐fatal cases requiring hospitalization were identified through the regional hospital discharge system using International Classification of Diseases. Results Mean follow‐up was 5.0 ± 1.6 and 4.4 ± 2.0 years for death and cardiac events, respectively; during follow‐up, 33 and 11 deaths were observed in the glibenclamide and gliclazide groups, with a yearly mortality rate of 4.3 and 2.2%, respectively (p < 0.05). At Cox regression, after adjustment for potential confounders, including comorbidity, glibenclamide treatment was associated with a significant increase in all‐cause mortality [OR 2.1(1.2;2.7), p < 0.05], while the difference in cardiovascular mortality was not statistically significant after adjustment for age and sex. Mortality for malignancies was significantly higher in patients treated with glibenclamide after adjustment for age, sex, BMI, and insulin and metformin treatment, [OR 3.6(1.1;11.9); p < 0.05]. A higher incidence of cardiac events was associated with glibenclamide treatment only in patients with previously known ischaemic heart disease. Conclusions Treatment with glibenclamide could be associated with higher mortality for cardiovascular diseases and malignancies, in comparison with gliclazide. Copyright © 2007 John Wiley & Sons, Ltd.