title: Intranasal insulin attenuates the hypothalamic-pituitary-adrenal axis response to psychosocial stress.
abstract: Previous studies have shown that intranasally administered insulin exerts an inhibitory influence on the basal hypothalamic-pituitary-adrenal (HPA) axis activity. To date, however, it remains unclear as to whether intranasal insulin does furthermore affect HPA axis responsiveness in situations of stress. Here, we tested whether intranasally administered insulin attenuates the HPA axis response to psychosocial stress. Fifty minutes before being exposed to the Trier Social Stress Test (TSST), 26 healthy young male participants received a single intranasal dose of human insulin (40 I.U.) or placebo in a placebo controlled, double-blind between-subject design. Plasma cortisol, saliva cortisol, heart rate, and blood pressure were measured at resting baseline and in response to the TSST. Plasma cortisol (P<.001) and saliva cortisol (P<.001) increased in response to stress, as did heart rate (P<.001) and blood pressure (P<.001). Intranasal insulin did not influence plasma or saliva cortisol, heart rate, blood pressure, blood glucose, and plasma insulin levels at baseline. However, intranasal insulin diminished the saliva cortisol (two-way ANOVA; treatment by time interaction: P=.05) and plasma cortisol (two-way ANOVA; treatment by time interaction: P=.05) response to the TSST without affecting heart rate, and blood pressure stress reactivity. Our data show that a single intranasal insulin administration effectively lowers stress-induced HPA axis responsiveness. Intranasal insulin may offer a therapeutic potential to prevent hyperactivity of the HPA system.
authors.affiliation: Department of Clinical Physiology, University of Trier, Johanniterufer 15, 54290 Trier, Germany. boeh1303@uni-trier.de
authors.forename: Andreas
authors.initials: A
authors.lastname: Bohringer
authors.forename: Lars
authors.initials: L
authors.lastname: Schwabe
authors.forename: Steffen
authors.initials: S
authors.lastname: Richter
authors.forename: Hartmut
authors.initials: H
authors.lastname: Schachinger
mesh_terms: D000281:Administration, Intranasal; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001794:Blood Pressure / Q000502:physiology; D004562:Electrocardiography; D006339:Heart Rate / Q000502:physiology; D006728:Hormones / Q000097:blood / Q000378:metabolism; D006801:Humans; D006854:Hydrocortisone / Q000097:blood / Q000378:metabolism; D007004:Hypoglycemic Agents / Q000009:adverse effects / Q000097:blood / Q000627:therapeutic use*; D007030:Hypothalamo-Hypophyseal System / Q000503:physiopathology*; D007328:Insulin / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use*; D008297:Male; D009483:Neuropsychological Tests; D010913:Pituitary-Adrenal System / Q000503:physiopathology*; D012463:Saliva / Q000737:chemistry; D012931:Social Environment; D013315:Stress, Psychological / Q000188:drug therapy* / Q000523:psychology; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D006728:Hormones; D007004:Hypoglycemic Agents; D007328:Insulin; D006854:Hydrocortisone