Hyperglycaemia has been observed after acute stroke, and is associated
with a poor prognosis. It is not known whether this is due to the str
ess response of the acute illness or whether hyperglycaemia is, in its
elf, harmful to ischaemic nervous tissue. Seventy-one patients admitte
d to hospital with acute stroke and no history of diabetes or other ac
ute 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 follow
ed up for 3 months or until death. Glucose levels were higher in subje
cts who died during the course of the study (p=0.025), but this relati
onship became non-significant after age (p<0.001) and cortisol (p=0.00
1) levels were taken into account with multivariate analysis. The corr
elation between serum cortisol and the volume of the lesion on CT scan
was also stronger than the relation of glucose with volume. Haemoglob
in A1c had no relationship with either mortality or lesion volume. The
se 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 fin
dings have implications for the treatment of acute stroke with hypogly
caemic agents.