Study population
We performed a single-center, retrospective, observational study. Patients with acute ischemic stroke who were hospitalized in West China Hospital, Sichuan University from May 1, 2018 to October 1, 2019 were enrolled. The inclusion criteria were as follows: (1) age≄18 years, (2) ischemic stroke confirmed by clinical symptoms and computed tomography (CT) or magnetic resonance imaging (MRI) on admission, (3)ischemic stroke onset within 48 hours before admission. The exclusion criteria were as follows: (1) history of thyroid diseases such as hyperthyroidism or hypothyroidism, (2) acute hemorrhagic stroke and transient ischemic stroke. The diagnosis and treatment of all patients with acute ischemic stroke were based on Chinese guidelines (17).