RESUMO
Stroke is one of the leading causes of death and probably the greatest cause of adult disability worldwide. Diabetes mellitus (DM) is a state of accelerated aging of blood vessels. Patients with diabetes have increased risk of stroke. Hyperglycemia represents a risk factor for poor outcome following stroke, and probably is just a marker of poor outcome rather than a cause. Lowering of blood glucose levels has not been shown to improve prognosis. Also, prevention of stroke risk among patients with DM is not improved with therapy for reduction of glucose levels. On the other hand, prediabetes, a metabolic state between normal glucose metabolism and diabetes, is a risk factor for the development of DM type 2 and subsequently for stroke. Several methods are known to identify prediabetes patients, including fasting plasma glucose levels, 2-hour post load glucose levels, and glycosylated hemoglobin levels. In this text, we tried to summarize known data about diagnosis, epidemiology, risk factors, pathophysiology, and prevention of prediabetes in relation to DM and stroke.