Measurement of Salivary Cortisol & Cortisone by LC-MS/MS
Research type
Research Study
Full title
Measurement of Salivary Cortisol and Cortisone by Novel TurboFlowTM Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS)
IRAS ID
89837
Contact name
Royce P Vincent
Contact email
Research summary
Cortisol production is regulated by the hypothalamic-pituitary-adrenal (HPA) axis. In clinical practice, the integrity of the HPA axis is assessed by measuring total serum cortisol at baseline and following dynamic stimulation or suppression of the HPA axis, usually to diagnose suspected adrenal insufficiency or hypercortisolism. In recent years, measurement of the steroid hormone cortisol in saliva has gained an important role in assessing the control mechanism for its production by the adrenal glands, thanks to the advantages of non-invasive sampling, good correlation between salivary cortisol and biologically active serum cortisol (not bound to serum proteins). It overcomes the limitation of total serum cortisol measurement in patients with altered cortisol binding proteins (such as in those using the oral contraceptive pill). Furthermore, it has been recommended as a first-line diagnostic test for Cushing’s syndrome (a disorder of cortisol excess). Currently the routinely used method for measuring salivary cortisol concentrations is immunoassay. The major limitation of this method, especially at very low concentrations, is interference by administered cortisol analogues and adrenal cortisol precursors and breakdown products. However, a potential source of analytical imprecision with clear clinical implications is the high cortisone concentrations found in saliva. This is rarely accounted for when reporting salivary cortisol measurements. Because it is structurally similar, it has the potential to interfere in cortisol immunoassays.
Previous studies have shown that liquid chromatography-mass spectrometry (LC-MS/MS) can measure salivary cortisol and cortisone simultaneously. We aim to utilise our recently acquired LC-MS/MS analyser with novel TurboFlow technology (ThermoFisher Scientific) to establish sensitive and precise values for salivary cortisol and cortisone in order to improve the diagnostic accuracy. This study will be carried out in our Supra-Regional Assay and Advisory Service (SAAS) Steroid Laboratory which is one of only two in England.
REC name
London - Dulwich Research Ethics Committee
REC reference
13/LO/0914
Date of REC Opinion
15 Aug 2013
REC opinion
Further Information Favourable Opinion