In patients with prediabetes and ischemic stroke or TIA, lifestyle optimization (ie, healthy diet, regular physical activity, and smoking cessation) can be beneficial for the preven- tion of progression to diabetes.237,238 In patients with TIA or ischemic stroke, it is reasonable to screen for prediabetes/dia- betes using HbA1c which, among available methods (HbA1c, fasting plasma glucose, oral glucose tolerance), has the advantage of convenience because it does not require fast- ing and is measured in a single blood sample. In patients with an ischemic stroke or TIA who also have diabetes, the usefulness of achieving intensive glucose control (ie, HbA1c 7%) beyond the acute phase of the ischemic event for prevention of recurrent stroke is unknown.239 244 In patients with prediabetes and ischemic stroke or TIA, particularly those with a body mass index (BMI) 35 kg/mP2 those <60 years of age, or women with a history of gestational diabetes, metformin may be beneficial to control blood sugar and to prevent progression to diabetes.245 247 In patients 6 months after TIA or ischemic stroke with insulin resistance, HbA1c <7.0%, and without heart failure or bladder cancer, treatment with pioglitazone may be consid- ered to prevent recurrent stroke.248 Synopsis The principal disorders of glucose metabolism are type 1 diabetes, T2D, and prediabetes. Type 1 diabetes is an autoimmune disorder that results in absolute insu- lin deficiency and accounts for 6% of diabetes in the United States. T2D results from progressive impairment in peripheral insulin sensitivity and pancreatic insulin secretion. It accounts for 91% of diabetes in the United CLINICAL STATEMENTS AND GUIDELINES Kleindorfer States. Prediabetes has the same pathophysiology as T2D but is associated with lower plasma glucose than in T2D. 