Stroke and diabetes: a dangerous liaison

Ischaemic stroke is a major cause of disability and death and the incidence rate of ischaemic stroke is doubled in patients who have diabetes. Admission hyperglycaemia in acute stroke patients is associated with higher mortality, longer hospital stay and worse functional outcome. However, it remains unclear whether hyperglycaemia is in fact a marker of stroke severity or whether hyperglycaemia directly contributes to brain damage. Potential mechanisms of hyperglycaemia related brain damage in stroke include acidosis, oxidative stress and reperfusion injury. Evidence suggests a potential benefit of treatment of hyperglycaemia with insulin in acute stroke patients but the potential for morbidity caused hypoglycaemia should be considered. The American Heart Association/American Stroke Association guidelines recommend maintaining the blood glucose level in the range 7.8–10 mmol/L during acute stroke hospitalisation whilst the European Stroke Organization guideline recommends lowering the blood glucose with insulin to below 10 mmol/L. More research is needed to explore the impact of admission hyperglycaemia and hypoglycaemia on stroke outcomes and the role of other glucose lowering therapies.