Albumin synthesis rates are not responsive to hyperglycemic hyperinsulinemia in postoperative patients

Abstract

Background: Insulin regulates albumin synthesis in vitro and in various experimental models. The current study was undertaken to determine the effects of a physiologic hyperinsulinemia on albumin synthesis in postoperative patients in whom plasma albumin concentrations are decreased. Methods: Studies were performed in postabsorptive patients after major abdominal operations. Mass spectrometry techniques were used to directly determine the incorporation rate of 1-[ 13C]-leucine into albumin. Consecutive blood samples were taken during a continuous isotope (D-Glc) infusion (0.16 μmol/kg/min). Isotopic enrichments were determined at baseline (period I) and after a 4-hour D-glucose (D-Glc) infusion at currently recommended rates (170 mg/kg/h, n = 10) or after infusion of saline (control group, n = 8) (period II). Results: After D-Glc infusion, plasma insulin concentrations increased significantly (period I, 6.6 ± 1.8 μU/mL; period II, 21.4 ± 2.1 μU/mL; P