[Portal blood immunoreactive insulin concentration after glucose infusion in elderly patients during gastrectomy...

We evaluated the effect of aging on portal blood immunoreactive insulin concentration, AKBR, and keton body concentration (acetoacetate + beta-hydroxybutyrate) after glucose infusion (25 g glucose in an hour) in patients undergoing gastrectomy. Twenty-seven patients studied were elderly (above 65 years) and twenty-eight were younger (below 60 years). There was no significant difference in portal blood immunoreactive insulin concentration after glucose infusion between the two groups of patients. In elderly patients, however, AKBR was significantly lower and keton body concentration was significantly higher than those in younger patients, and these imply that suppression of ketogenesis and activation of hepatic mitochondrial function due to insulin may be reduced in elderly patients. These findings suggest that, during gastrectomy, pancreatic insulin secretion may not be impaired in elderly patients, but insulin action may be attenuated with aging.