Acute effects of hydrocortisone on the metabolic response to a glucose load: increase in the first-phase insulin secretion

Several basic science studies support the existence of non-genomic glucocorticoid signaling in pancreas, liver, and adipocytes, but its clinical relevance has not yet been elucidated. This study aimed at investigating the rapid effects of hydrocortisone on the human metabolic response to glucose.In a randomized placebo-controlled crossover study, ten healthy men received an i.v. bolus of 0.6 mg/kg hydrocortisone once and placebo once 4 min before the administration of 330 mg/kg glucose. Cortisol, glucose, insulin, C-peptide, ghrelin, and peptide YY (PYY) levels were measured during the following 3 h. Minimal model analysis was performed for evaluating the metabolic response.Hydrocortisone attenuated the rise in plasma glucose during the initial 15 min following glucose administration (P=0.039), and it led to lower glucose levels during the first 2 h (P=0.017). This was accompanied by enhanced circulating insulin (P=0.02) and C-peptide (P=0.03) levels during the initial 15 min, and a 35% increase in the first-phase beta-cell function (P=0.003). Hydrocortisone decreased PYY concentrations during the initial 30 min (P=0.014), but it did not affect the ghrelin response to glucose.One i.v. bolus of hydrocortisone induces rapid effects on carbohydrate metabolism increasing the first-phase beta-cell function. The modulation of PYY plasma levels suggests the possible non-genomic effects of glucocorticoids on appetite-regulatory hormones.