Adipose tissue 11β-hydroxysteroid dehydrogenase type 1 expression in obesity and Cushing's syndrome

Objective: To evaluate the expression of 11 beta-hydrxysteroid dehydrogenase type 1 (11 beta-HSD1) in omental adipose tissue of patients with Cushing's syndrome and simple obesity, compared with normal weight controls. Design and methods: We have performed a case-control study and studied omental adipose tissue from a total of 24 subjects (eight obese subjects, ten patients with Cushing's syndrome due to adrenal adenoma, and six normal weight controls). Body mass index, blood pressure, plasma glucose, plasma insulin, plasma cortisol, urinary free cortisol and post dexamethasone plasma cortisol were measured with standard methods. 11 beta-HSD1 mRNA and protein expression were evaluated in real-time PCR and western blot analysis respectively. Results: 11 beta-HSD1 mRNA was 13-fold higher in obese subjects compared with controls (P = 0.001). No differences were found between Cushing's patients and controls. Western blot analysis supported the mRNA expression results. Conclusions: Our data show the involvement of 11 beta-HSD1 enzyme in visceral obesity, which is more evident in severely obese patients than in Cushing's syndrome patients. The lack of increase of 11 beta-HSD1 expression in Cushing's syndrome could suggest downregulation of the enzyme as a result of long-term overstimulation.