Subcutaneous Adipose 11β-Hydroxysteroid Dehydrogenase Type 1 Activity and Messenger Ribonucleic Acid Levels Are Associated with Adiposity and Insulinemia in Pima Indians and Caucasians

Metabolic effects of cortisol may be critically modulated by glucocorticoid metabolism in tissues. Specifically, active cortisol is regenerated from inactive cortisone by the enzyme 11 beta-hydroxysteroid dehydrogenase type 1 (11-HSD1) in adipose and liver. We examined activity and mRNA levels of 11-HSD1 and tissue cortisol and cortisone levels in sc adipose tissue biopsies from 12 Caucasian (7 males and 5 females) and 19 Pima Indian (10 males and 9 females) nondiabetic subjects aged 28 +/- 7.6 yr (mean +/- SD; range, 18-45). Adipose 11-HSD1 activity and mRNA levels were highly correlated (r = 0.51, P = 0.003). Adipose 11-HSD1 activity was positively related to measures of total (body mass index, percentage body fat) and central (waist circumference) adiposity (P < 0.05 for all) and fasting glucose (r = 0.43, P = 0.02), insulin (r = 0.60, P = 0.0005), and insulin resistance by the homeostasis model (r = 0.70, P < 0.0001) but did not differ between sexes or ethnic groups. Intra-adipose cortisol was positively associated with fasting insulin (r = 0.37, P = 0.04) but was not significantly correlated with 11-HSD1 mRNA or activity or with other metabolic variables. In this cross-sectional study, higher adipose 11-HSD1 activity is associated with features of the metabolic syndrome. Our data support the hypothesis that increased regeneration of cortisol in adipose tissue influences metabolic sequelae of human obesity.