title: Tissue-specific changes in peripheral cortisol metabolism in obese women: increased adipose 11beta-hydroxysteroid dehydrogenase type 1 activity.
abstract: Cushing's syndrome and the metabolic syndrome share clinical similarities. Reports of alterations in the hypothalamic-pituitary-adrenal (HPA) axis are inconsistent, however, in the metabolic syndrome. Recent data highlight the importance of adipose 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1), which regenerates cortisol from cortisone and, when overexpressed in fat, produces central obesity and glucose intolerance. Here we assessed the HPA axis and 11beta-HSD1 activity in women with moderate obesity and insulin resistance. Forty women were divided into tertiles according to body mass index (BMI; median, 22.0, 27.5, and 31.4, respectively). Serum cortisol levels were measured after iv CRH, low dose dexamethasone suppression, and oral cortisone administration. Urinary cortisol metabolites were measured in a 24-h sample. A sc abdominal fat biopsy was obtained in 14 participants for determination of 11beta-HSD type 1 activity in vitro. Higher BMI was associated with higher total cortisol metabolite excretion (r = 0.49; P < 0.01), mainly due to increased 5alpha- and, to a lesser extent, 5beta-tetrahydrocortisol excretion, but no difference in plasma cortisol basally, after dexamethasone, or after CRH, and only a small increase in the ACTH response to CRH. Hepatic 11beta-HSD1 conversion of oral cortisone to cortisol was impaired in obese women (area under the curve, 147,736 +/- 28,528, 115,903 +/- 26,032, and 90,460 +/- 18,590 nmol/liter.min; P < 0.001). However, 11beta-HSD activity in adipose tissue was positively correlated with BMI (r = 0.55; P < 0.05). In obese females increased reactivation of glucocorticoids in fat may contribute to the characteristics of the metabolic syndrome. Increased inactivation of cortisol in liver may be responsible for compensatory activation of the HPA axis. These alterations in cortisol metabolism may be a basis for novel therapeutic strategies to reduce obesity-related complications.
authors.affiliation: Department of Public Health and Clinical Medicine, Umeå University Hospital, Umeå, Sweden 90185.
authors.forename: Eva
authors.initials: E
authors.lastname: Rask
authors.forename: Brian R
authors.initials: BR
authors.lastname: Walker
authors.forename: Stefan
authors.initials: S
authors.lastname: Söderberg
authors.forename: Dawn E W
authors.initials: DE
authors.lastname: Livingstone
authors.forename: Mats
authors.initials: M
authors.lastname: Eliasson
authors.forename: Owe
authors.initials: O
authors.lastname: Johnson
authors.forename: Ruth
authors.initials: R
authors.lastname: Andrew
authors.forename: Tommy
authors.initials: T
authors.lastname: Olsson
mesh_terms: D043205:11-beta-Hydroxysteroid Dehydrogenase Type 1; D000273:Adipose Tissue / Q000201:enzymology*; D000324:Adrenocorticotropic Hormone / Q000097:blood; D015992:Body Mass Index; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D006913:Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D000324:Adrenocorticotropic Hormone; D006913:Hydroxysteroid Dehydrogenases; D043205:11-beta-Hydroxysteroid Dehydrogenase Type 1; C468386:HSD11B1 protein, human; D006854:Hydrocortisone