Effects of hyperglycemia on cortical response to esophageal distension in normal subjects

Acute changes in the blood glucose concentration affect the intensity of ga strointestinal sensations. The aim of this study was to examine the effects of hyperglycemia on cortical potentials evoked by esophageal distension. I n 16 healthy volunteers, a balloon was positioned in the lower esophagus, A series of 50 distensions was performed at both a lower volume (producing d efinite sensation) and a higher volume (producing unpleasant sensation), at blood glucose concentrations of 5 and 13 mmol/liter. Triphasic cortical po tentials were recorded from a midline scalp electrode (Cz). During euglycem ia, interpeak amplitudes were greater at the higher than the lower balloon volume (P < 0.005). At the lower balloon volume, the interpeak amplitudes w ere greater during hyperglycemia than euglycemia (P < 0.05), There was no e ffect of the blood glucose concentration on amplitude at the higher balloon volume. We conclude that in healthy subjects, the amplitude of the cortica l response to moderate, but not unpleasant, esophageal distension is greate r during hyperglycemia when compared to euglycemia, These observations are consistent with the concept of increased intensity of gut sensation during hyperglycemia.