Comparative Effects of Sodium-Glucose Cotransporter 2 Inhibitor and Thiazolidinedione Treatment on Risk of Stroke among Patients with Type 2 Diabetes Mellitus

Background: Although cardiovascular outcome trials using sodium-glucose cotransporter-2 inhibitors (SGLT-2i) showed a reduction in risk of 3-point major adverse cardiovascular events (MACE), they did not demonstrate beneficial effects on stroke risk. Additionally, meta-analysis showed SGLT-2i potentially had an adverse effect on stroke risk. Contrarily, pioglitazone, a type of thiazolidinedione (TZD), has been shown to reduce recurrent stroke risk. Thus, we aimed to compare the effect of SGLT-2i and TZD on the risk of stroke in type 2 diabetes mellitus (T2DM) patients. Methods: Using the Korean National Health Insurance Service data, we compared a 1:1 propensity score-matched cohort of patients who used SGLT-2i or TZD from January 2014 to December 2018. The primary outcome was stroke. The secondary outcomes were myocardial infarction (MI), cardiovascular death, 3-point MACE, and heart failure (HF). Results: After propensity-matching, each group included 56,794 patients. Baseline characteristics were well balanced. During the follow-up, 862 patients were newly hospitalized for stroke. The incidence rate of stroke was 4.11 and 4.22 per 1,000 person-years for the TZD and SGLT-2i groups respectively. The hazard ratio (HR) of stroke was 1.054 (95% confidence interval [CI], 0.904 to 1.229) in the SGLT-2i group compared to the TZD group. There was no difference in the risk of MI, cardiovascular death, 3-point MACE between groups. Hospitalization for HF was significantly decreased in SGLT-2i-treated patients (HR, 0.645; 95% CI, 0.466 to 0.893). Results were consistent regardless of prior cardiovascular disease. Conclusion: In this real-world data, the risk of stroke was comparable in T2DM patients treated with SGLT-2i or TZD.