Hyperglycemia in acute ischemic stroke: pathophysiology and clinical management

Patients with acute ischemic stroke frequently test positive for hyperglycemia, which is associated with a poor clinical outcome. This association between poor glycemic control and an unfavorable prognosis is particularly evident in patients with persistent hyperglycemia, patients without a known history of diabetes mellitus, and patients with cortical infarction. To date, however, only one large clinical trial has specifically investigated the effect of glycemic control on stroke outcome. This trial failed to show a clinical benefit, but had several limitations. Despite a lack of clinical evidence supporting the use of glycemic control in the treatment of patients with stroke, international guidelines recommend treating this subset of critically ill patients for hyperglycemia in the hospital setting. This treatment regime is, however, particularly challenging in patients with stroke, and is associated with an increased risk of the patient developing hypoglycemia. Here we review the available evidence linking hyperglycemia to a poor clinical outcome in patients with ischemic stroke. We highlight the pathophysiological mechanisms that might underlie the deleterious effects of hyperglycemia on acute stroke prognosis and systematically review the literature concerning tight glycemic control after stroke. Finally, we provide directions on the use of insulin treatment strategies to control hyperglycemia in this patient group.