Association between Body Mass Index and Stroke Risk Among Patients with Type 2 Diabetes

Context Very few studies focused on the association between body mass index (BMI) and stroke risk among patients with diabetes. Objective We aimed to investigate the association between BMI and stroke risk in patients with type 2 diabetes. Design Demographic, anthropometric, laboratory, and medication information were extracted from the National Patient-Centered Clinical Research Network common data model. Participants We performed a retrospective cohort study of 67 086 patients with type 2 diabetes. Main Outcome Measures Incident stroke including both ischemic and hemorrhagic stroke were defined. Results During a mean follow up of 3.74 years. 8918 incident stroke events occurred. Multivariable-adjusted hazard ratios across different categories of BMI at baseline (18.5–24.9 [reference group], 25.0–29.9, 30.0–34.9, 35.0–39.9, and ≥40 kg/m2) were 1.00, 0.92, 0.85, 0.74, and 0.63 (Ptrend <0.001) for total stroke; 1.00, 0.93, 0.88, 0.77, and 0.65 (Ptrend <0.001) for ischemic stroke; and 1.00, 0.79, 0.50, 0.50, and 0.41 (Ptrend <0.001) for hemorrhagic stroke, respectively. When we used an updated mean value of BMI, the graded inverse association of body mass index with stroke risk did not change. This linear association was consistent among patients of different subgroups. Further sensitivity analysis excluding patients who were diagnosed stroke within 6 months after first diagnosis of type 2 diabetes or including non-smokers only also confirmed our findings. Conclusion The present study found an inverse association between BMI and the risk of total, ischemic, and hemorrhagic stroke among patients with type 2 diabetes. More clinical and molecular insights are still needed in explaining these findings.