No effect of free fatty acids on adrenocorticotropin and cortisol secretion in healthy young men.
Free fatty acids (FFAs) affect anterior pituitary function. However, the effect of FFAs on corticotropin (ACTH) and cortisol in humans is controversial. Thus, we assessed the effect of a pronounced increase in circulating FFA levels induced by infusion of lipid/heparin on ACTH and cortisol secretion in young men. Eight healthy male volunteers who underwent a 10-hour overnight fast were investigated. A 20% lipid/heparin or saline/heparin infusion was given at a rate of 1.5 mL/min for 6 hours. A euglycemic hyperinsulinemic clamp was performed in 6 subjects 4 hours after the start of infusion. To assess steroid metabolism, we measured ACTH, cortisol, FFAs, and urinary steroids. Lipid infusion increased FFAs (6.06 +/- 0.52 vs 0.70 +/- 0.23 mmol/L; P < .005) and induced insulin resistance (glucose infusion rate, 4.08 +/- 2.15 vs 6.02 +/- 2.60 mg/kg per minute; P < .005). Serum cortisol and plasma ACTH decreased independent of lipid/heparin or saline/heparin infusion. In addition, we found no effect of hyperinsulinemia on ACTH and cortisol levels. There were no differences in urinary free cortisol, urinary free cortisone, 5beta-tetrahydrocortisol, 5alpha-tetrahydrocortisol, and tetrahydrocortisone. In conclusion, FFAs had no effect on basal ACTH and cortisol secretion in normal-weight young men. In addition, no alterations in urinary glucocorticoid metabolites were detected, suggesting unchanged cortisol metabolism during lipid infusion.
Mai
Knut
K
Department of Endocrinology, Diabetes and Nutrition, Charite-University Medicine Berlin, Campus Benjamin Franklin, 12200 Berlin, Germany. knut.mai@charite.de
Bobbert
Thomas
T
Kullmann
Volker
V
Andres
Janin
J
Bähr
Volker
V
Maser-Gluth
Christiane
C
Rochlitz
Helmut
H
Spranger
Jochen
J
Diederich
Ssven
S
Pfeiffer
Andreas F H
AF
D000324:Adrenocorticotropic Hormone / Q000378:metabolism* / Q000652:urine; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D004041:Dietary Fats / Q000494:pharmacology; D005230:Fatty Acids, Nonesterified / Q000502:physiology*; D015309:Glucose Clamp Technique; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism* / Q000652:urine; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D007328:Insulin / Q000097:blood; D008297:Male; D011446:Prospective Studies; D018401:Sample Size; D013256:Steroids / Q000652:urine
D001786:Blood Glucose; D004041:Dietary Fats; D005230:Fatty Acids, Nonesterified; D007328:Insulin; D013256:Steroids; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone