1. ^*Division of Endocrinology and Metabolism, Department of Internal Medicine, Medical University of Vienna, Vienna, Austria.
2. ^†Section of Clinical Biometrics, Medical Statistics and Informatics, Medical University of Vienna, Vienna, Austria.

Correspondence: Heinrich Vierhapper Clinical Division of Endocrinology and Metabolism, Department of Internal Medicine III, Währinger Gürtel 18–20, A-1090 Wien, Austria. E-mail: heinrich.vierhapper@meduniwien.ac.at

^*The costs of publication of this article were defrayed, in part, by the payment of page charges. This article must, therefore, be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

Received 3 November 2005; Revised  00; Accepted 29 September 2006.

Abstract

Objective: Our objective was to demonstrate that the smaller oxoreductase activity of 11-HSD1 in women would shift the interconversion of cortisol and cortisone toward cortisone, resulting in a larger amount of generated labeled cortisone in healthy women than in healthy men.

Research Methods and Procedures: Using mass spectrometry, the amount of cortisone generated from a continuous infusion (8 AM to 6 PM) of stable-labeled cortisol (1,2-d-cortisol) was determined in non-obese and in obese (BMI >35 kg/m²) men and women during steady-state conditions (from 2 PM to 6 PM). In this setting, the amount of generated labeled cortisone (expressed as % of the achieved steady-state concentrations of labeled cortisol) reflects the sum of the bi-directional conversion of cortisol into cortisone (and vice versa) by 11-hydroxysteroid dehydrogenase.

Results: The amount of generated labeled cortisone was higher in men than in women (p < 0.0001). This sex difference was higher in obese than in non-obese patients (p = 0.0062).

Conclusions: The interconversion of cortisol and cortisone during steady-state conditions is shifted toward cortisol in men as compared with women. This suggests a higher overall oxoreductase activity of 11-hydroxysteroid dehydrogenase type 1 in men than in women. This sex-specific difference is maintained in obesity.