Stroke risk in treatment of type 2 diabetes in China: a 7 year retrospective cohort study

BackgroundDiabetes and stroke are leading causes of death and disability, and major public health concerns in China, which accounts for 25% of patients with diabetes worldwide. Type 2 diabetes is an independent risk factor for cerebral ischaemia and accounts for about 20% of stroke cases. We previously showed that KATP channel activation provides neuroprotection against cerebral ischaemia and that sulfonylureas blocking these channels increase the stroke risk in patients with type 2 diabetes. We aimed to further determine whether different classes of antidiabetic drugs increase the risk of stroke in Chinese patients with type 2 diabetes.MethodsIn this retrospective cohort study, we used data from medical records (Jan 1, 2008, to Dec 30, 2015) of the Endocrinology Division of the Third Affiliated Hospital of Jilin University, Jilin, China. Patients aged 32–80 years with type 2 diabetes whose blood glucose control treatment included sulfonylureas, metformin, insulin, or restricted diet were eligible for inclusion. All patients also received education on diet, exercise, blood glucose monitoring, and other aspects of diabetes management. We used χ2 test was to determine significance (p<0·05) between two sets of categorical data and Student's t-test for continuous data. To determine the overall risk, we used multivariate logistic regression with stroke occurrence as the dependent variable and hypoglycaemic drug as the independent variable. Ethics approval was granted by The Third Affiliated Hospital of Jilin University.Results1829 patients were eligible for inclusion, of whom 528 had sulfonylureas, 611 had metformin, 535 had insulin, and 155 were on a restricted diet. 55 individuals who switched to alternative therapy or were lost to follow-up were excluded, and 1774 patients were included in analysis. 116 cases of stroke were recorded: 42 in the sulfonylurea group, 29 in the metformin group, 36 in the insulin group, and nine in the restricted diet group. The risk of stroke in patients given sulfonylureas was increased by 2·65 times (95% CI 1·56–4·50) compared with those given metformin, 1·21 times (0·79–1·86) compared with those given insulin, 1·13 times (0·56–2.25) compared with those on a restricted diet, and 1·63 times (1·12–2·37) compared with all three non-sulfonylurea groups.InterpretationChinese patients with diabetes receiving sulfonylureas seem to have a higher risk of stroke than those using non-sulfonylurea antidiabetic treatments. Cardiovascular safety of antidiabetic drugs needs to be carefully assessed to improve health care and quality of life in Chinese patients with diabetes.FundingHeart and Stroke Foundation of Canada (G-13-0003069) and National Sciences and Engineering Research Council of Canada (NSERC-249962-09).