Hyperglycaemia and mortality from acute stroke

Abstract

Hyperglycaemia has been observed after acute stroke, and is associated with a poor prognosis. It is not known whether this is due to the stress response of the acute illness or whether hyperglycaemia is, in itself, harmful to ischaemic nervous tissue. Seventy-one patients admitted to hospital with acute stroke and no history of diabetes or other acute illness were recruited, and fasting blood sampling was carried out within 24 h of symptom onset, for plasma glucose and stress hormones and levels of haemoglobin A1c (HbA1c). Computerized tomography of the brain was carried out on 77% of the subjects. The subjects were followed up for 3 months or until death. Glucose levels were higher in subjects who died during the course of the study (p = 0.025), but this relationship became non-significant after age (p < 0.001) and cortisol (p = 0.001) levels were taken into account with multivariate analysis. The correlation between serum cortisol and the volume of the lesion on CT scan was also stronger than the relation of glucose with volume. Haemoglobin A1c had no relationship with either mortality or lesion volume. These findings suggest that the hyperglycaemia seen after an acute stroke is secondary to a stress response and they do not support the theory of hyperglycaemia being harmful to ischaemic nervous tissue. These findings have implications for the treatment of acute stroke with hypoglycaemic agents.