Cortisol homeostasis is implicated in
hypertension and
metabolic syndrome. Two
enzymes modulate
cortisol availability; 11β-hydroxysteroid
dehydrogenase type 1 (11β-HSD1) preferentially converts inactive
cortisone to
cortisol, whereas 11β-hydroxysteroid
dehydrogenase type 2 (11β-HSD2) converts
cortisol to
cortisone. In contrast, 5α and 5β
reductases inactivate
cortisol by conversion to its tetrahydrometabolites:
tetrahydrocortisol, allo-
tetrahydrocortisol and
tetrahydrocortisone. A subtle local increase in
cortisol can be detected by measuring 24-h urine metabolites, LC-MS/MS being the reference method. The 11β-HSD2 activity is assessed based on the
cortisol/
cortisone ratio, and the 11β-HSD1 activity on the (tetrahydrocortisol + allo-
tetrahydrocortisol)/
tetrahydrocortisone ratio. To better understand
hypertension and/or
metabolic syndrome pathogenesis a method for simultaneous determination of
cortisol,
cortisone,
tetrahydrocortisol, allo-
tetrahydrocortisol and
tetrahydrocortisone was developed and validated in an LC coupled with the new detector AB Sciex QTrap® 4500 tandem mass spectrometer. The
steroids were extracted from 1 mL urine, using cortisol-D4 as internal standard. The quantification range was 0.1-120 ng/mL for
cortisol and
cortisone, and 1-120 ng/mL for tetrahydrometabolites, with >89 % recovery for all analytes. The coefficient of variation and accuracy was <10 %, and 85-105 %, respectively. Our LC-MS/MS method is accurate and reproducible in accordance with Food and Drug Administration guidelines, showing good sensitivity and recovery. This method allows the assessment of 11β-HSD2 and 11β-HSD1 activities in a single analytical run providing an innovative tool to explain etiology of misclassified
essential hypertension and/or
metabolic syndrome.