Kinetics of dexamethasone-induced alterations of glucose metabolism in healthy humans

Am J Physiol. 1998 Nov;275(5):E806-13. doi: 10.1152/ajpendo.1998.275.5.E806.


Six healthy human subjects were studied during three 75-g oral, [13C]glucose tolerance tests to assess the kinetics of dexamethasone-induced impairment of glucose tolerance. On one occasion, they received dexamethasone (4 x 0.5 mg/day) during the previous 2 days. On another occasion, they received a single dose (0. 5 mg) of dexamethasone 150 min before ingestion of the glucose load. On the third occasion, they received a placebo. Postload plasma glucose was significantly increased after both 2 days dexamethasone and single dose dexamethasone compared with control (P < 0.05). This corresponded to a 20-23% decrease in the metabolic clearance rate of glucose, whereas total glucose turnover ([6,6-2H]glucose), total (indirect calorimetry) and exogenous glucose oxidation (13CO2 production), and suppression of endogenous glucose production were unaffected by dexamethasone. Plasma insulin concentrations were increased after 2 days of dexamethasone but not after a single dose of dexamethasone. In a second set of experiments, the effect of a single dose of dexamethasone on insulin sensitivity was assessed in six healthy humans during a 2-h euglycemic hyperinsulinemic clamp. Dexamethasone did not significantly alter insulin sensitivity. It is concluded that acute administration of dexamethasone impairs oral glucose tolerance without significantly decreasing insulin sensitivity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Blood Glucose / drug effects
  • Blood Glucose / metabolism*
  • Carbon Dioxide / analysis
  • Carbon Isotopes
  • Dexamethasone / pharmacology*
  • Female
  • Glucose / metabolism*
  • Glucose Clamp Technique
  • Glucose Tolerance Test
  • Humans
  • Infusions, Intravenous
  • Insulin / administration & dosage
  • Insulin / blood
  • Insulin / pharmacology
  • Kinetics
  • Male
  • Reference Values
  • Time Factors


  • Blood Glucose
  • Carbon Isotopes
  • Insulin
  • Carbon Dioxide
  • Dexamethasone
  • Glucose