Glucose homeostasis and insulin secretion during isoflurane anesthesia in humans.

The effect of isoflurane-air anesthesia on glucose tolerance in humans was investigated using two successive intravenous glucose tolerance tests (IVGTT). After a first IVGTT while awake, patients received a second IVGTT either while awake (group I), during anesthesia with isoflurane-air and pancuronium without surgical stimulation (group II), or during the same anesthetic technique but combined with surgery (group III). Isoflurane seemed to induce glucose intolerance (glucose disappearance rate K10-60 min = 1.628 +/- 0.462% min-1 [control] versus 1.086 +/- 0.920% min-1 [anesthesia], P less than 0.05) partly due to a decreased glucose induced insulin response. Growth hormone and norepinephrine levels were also increased during anesthesia. Epinephrine levels were lowered by isoflurane anesthesia. Although glucose intolerance was marked during surgery (K10-60 min = 0.892 +/- 0.286% min-1), the glucose-induced insulin response remained similar to that observed in patients in group II, while growth hormone, cortisol, epinephrine, and norepinephrine concentrations increased significantly. These known stress factors thus seemed to enhance glucose intolerance through a diminished response to insulin action and/or an enhanced hepatic glucose output, rather than by further impairing pancreatic insulin secretion.