Cortisol clearance and associations with insulin sensitivity, body fat and fatty liver in middle-aged men.
OBJECTIVE
The regulation of cortisol metabolism in vivo is not well understood. We evaluated the relationship between cortisol metabolism and insulin sensitivity, adjusting for total and regional fat content and for non-alcoholic fatty liver disease.


METHODS
Twenty-nine middle-aged healthy men with a wide range of BMI were recruited. We measured fat content by dual-energy X-ray absorptiometry and magnetic resonance imaging (MRI), liver fat by ultrasound and MRI, the hypothalamic-pituitary-adrenal axis by adrenal response to ACTH(1-24), unconjugated urinary cortisol excretion, corticosteroid-binding globulin, and cortisol clearance by MS. We assessed insulin sensitivity by hyperinsulinaemic-euglycaemic clamp and by OGTT.


RESULTS
Cortisol clearance was strongly inversely correlated with insulin sensitivity (M value) (r = -0.61, p = 0.002). Cortisol clearance was increased in people with fatty liver compared with those without (mean+/-SD: 243 +/- 10 vs 158 +/- 36 ml/min; p = 0.014). Multiple regression modelling showed that the relationship between cortisol clearance and insulin sensitivity was independent of body fat. The relationship between fatty liver and insulin sensitivity was significantly influenced by body fat and cortisol clearance.


CONCLUSIONS
Cortisol clearance is strongly associated with insulin sensitivity, independently of the amount of body fat. The relationship between fatty liver and insulin sensitivity is mediated in part by both fatness and cortisol clearance.
Holt
H B
HB
Endocrinology and Metabolism, DOHaD Division, University of Southampton, Southampton, UK.
Wild
S H
SH
Postle
A D
AD
Zhang
J
J
Koster
G
G
Umpleby
M
M
Shojaee-Moradie
F
F
Dewbury
K
K
Wood
P J
PJ
Phillips
D I
DI
Byrne
C D
CD
D000273:Adipose Tissue / Q000033:anatomy & histology*; D001786:Blood Glucose / Q000032:analysis; D001823:Body Composition; D015992:Body Mass Index; D005234:Fatty Liver / Q000097:blood / Q000503:physiopathology*; D005947:Glucose / Q000378:metabolism; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007328:Insulin / Q000097:blood*; D008055:Lipids / Q000097:blood; D008297:Male; D008657:Metabolic Clearance Rate; D024821:Metabolic Syndrome / Q000097:blood / Q000503:physiopathology; D008875:Middle Aged; D008954:Models, Biological; D012044:Regression Analysis
D001786:Blood Glucose; D007328:Insulin; D008055:Lipids; D005947:Glucose; D006854:Hydrocortisone