Endocrine Abstracts

For a long time it has been suggested that glucocorticoids (GC) mediate their effects solely on the genomic level. A number of studies reported an existence of rapid GC effects independent on gene expression. These effects may play an important role in stress response or during acute GC therapy. As far as we know, rapid inhibitory GC effects on glucose-induced secretion of insulin have been reported only in animals (1). The aim of our study was to evaluate effects of GC on early phase of insulin secretion in subjects with normal fasting glycemia.

Methods: Seven healthy lean women (BMI 20.7±0.3 kg/m², age 28.6±1.2 years) and seven overweight women (BMI 28.9±1.1 kg/m², age 29.4±1.5 years) participated on the study. The dose of 20 mg of hydrocortisone (HC) or isotonic saline solution was intravenously administrated during 5 min. Immediately afterwards, 40% glucose solution (0.1g/kg) was injected during 1 min. Blood samples for determination of insulin, C-peptide and glucose were drawn in frequent intervals during 30 min after glucose administration. Concentration of cortisol was determined before HC administration, then 16 and 30 min after glucose administration.

Results: The maximal cortisol concentration was 1179±71.9 nmol/l in the 16 min of investigation. In both groups, HC administration was followed by a significant glucose-induced increase of insulin and C-peptide with the peak 5 min after glucose infusion. HC administration did not influence glucose-induced responses of insulin and C-peptide in our group of normal and increased body weight females.

Conclusion: We did not confirm rapid non-genomic effect of acute hypercortisolemia on early phase of insulin secretion in normal and overweight females. Our results do not support rapid effects of GC on metabolic changes during acute short-term stress response in humans.

Literature: 1. Sutter-Dub MT: Steroids. 67:77-93, 2002.

The project was supported by grants VEGA 2/7178/27 a CENDO SAV.