Mortality and Cardiovascular Risk of Sulfonylureas in South Asian, Chinese and Other Canadians with Diabetes

Abstract Objectives Sulfonylureas have been inconsistently associated with increased cardiovascular mortality in patients with type 2 diabetes mellitus. However, there are no existing studies of long-term risk in South Asian and Chinese populations. Our objective was to determine whether sulfonylureas are associated with increased mortality or cardiovascular disease in a population cohort of South Asian, Chinese and other Canadian patients with incident diabetes. Methods We studied a population-based cohort of adults 35 years of age or older who had diabetes and had been diagnosed between April 2004 and March 2014 by using administrative databases from British Columbia. The primary outcome was time to death from any cause or from a major cardiovascular event (MACE) with sulfonylurea treatment within each ethnicity. Propensity score modelling was applied using inverse probability of treatment weights. Results were stratified by agent and adjusted for age, sex, comorbidities, income and other medications. Results We included 208 870 patients: 13 755 South Asians, 22 871 Chinese, 172 244 other Canadians. Mortality and MACEs were higher in other Canadian patients for whom sulfonylureas had been prescribed (adjusted HR = 2.0; 95% confidence interval 1.9 to 2.2; and HR = 1.9, 1.7 to 2.2). Among Chinese and South Asian patients who had been prescribed sulfonylureas, mortality (HR = 2.6, 2.0 to 3.5; and HR = 2.4, 1.7 to 3.4, respectively) and MACEs (HR = 2.3; 1.4 to 4.0; and HR = 2.0, 1.2 to 3.2, respectively) were elevated. Conclusions Considering the widespread use of sulfonylureas, there is a significant signal for increased mortality in all patients. In particular, increased mortality and MACEs were observed in South Asian and Chinese patients. These results should be confirmed in other studies, and patients of Asian descent should be included in clinical trials concerning diabetes.