Arbelaez AM, Powers WJ, Videen TO et al.
Washington University, St Louis, MO, USA.
Diabetes 2008;57:470–5.
Editor’s note: Investigation of regional cerebral metabolic effects during hypoglycemia in order to determine the potential triggers for hypoglycemia unawareness (and resultant impaired counter-regulatory responses) has recently become possible using positron emission tomography. In the present article, [
15O]water was used to trace cerebral blood flow (as a marker of neuronal activation) in non-diabetic individuals during two episodes of controlled hypoglycemia; the first at the beginning of day 2 and the second after 24 h of interprandial hypoglycemia – a proven method of inducing a state very similar to the hypoglycemia unawareness that occurs in diabetic patients. Interval hypoglycemia resulted in significantly blunted counter-regulatory responses on the second day of study, whilst cerebral blood flow changes during hypoglycemia were not different between day 1 and day 2, except in the dorsal midline nuclei of the thalamus.