An in vivo study of the cortisol-cortisone shuttle in subcutaneous abdominal adipose tissue

OBJECTIVE Previous in vitro studies have demonstrated significant 11-beta h ydroxysteroid dehydrogenase (11 beta-HSD) oxo-reductase activity in viscera l, but not subcutaneous adipose stromal cells. We have conducted an in vivo study of the cortisol-cortisone shuttle in subcutaneous abdominal adipose tissue. DESIGN We measured arteriovenous (A-V) differences in serum cortisol and co rtisone across subcutaneous abdominal adipose tissue and forearm muscle in a heterogeneous group of subjects. PATIENTS We studied 34 subjects (male:female = 12:22), age median (interqua rtile range) 45 (19-65) years, body mass index 32.7 (20.4-77.1) kg m(-2), t otal body fat 34.4 (5.6-119.1) kg, MEASUREMENTS Serum cortisol and cortisone were measured in serum samples fr om a radial artery, superficial epigastric vein and deep forearm vein. Abdo minal adipose and forearm blood flow rates were measured by (133)Xenon wash out and plethysmography, respectively. RESULTS For cortisone, there was significant (P < 0.001) clearance by adipo se tissue, with an A-V difference of 4 (1-7) nmol/l. For cortisol there was a trend for arterial concentrations (203 (142-292) nmol/l) to be lower tha n venous (225 (152-263) nmol/l), but this was not significant. The adipose tissue cortisone clearance rate correlated with total body fat (r = 0.35, P = 0.05). CONCLUSIONS We have demonstrated 11 beta-HSD oxo-reductase activity in subc utaneous abdominal adipose tissue, which may be increased in obesity.