In conclusion we recommend the overnight dexamethasone suppression test with measurement of salivary cortisol as a screening test for Cushing's syndrome.
night time salivary cortisol found to correlate with early morning urine samples in those with Cushing's. This in addition to the nocturnal salivary cortisol correlation found in past studies. The positive studies on salivary cortisol testing continues to build.
late-night salivary cortisol yields sensitivity of 92-100% and specificity of 93-100%. Wow! not much in medicine even approaches this kind of validity.
cortisol may act as a mineralocorticoid when in excess, perhaps by saturating the 11β-hydroxysteroid-dehydrogenase (11β-HSD2 enzyme) that inactivates cortisol at the renal tubule
high cortisol levels may be the principal cause of hypokalemic alkalosis
this study showed salivary cortisol to be an "excellent" means to evaluate both those with adrenal disease and adrenal dysfunction. Salivary test is a good tool to evaluate the free active cortisol.
Endocrine society clinical practice guideline's state proves validity of salivary cortisol testing. Statement: "the diagnostic sensitivity and specificity is said to be excellent (92-100%)" and " Measurement of salivary cortisol by ELISA and LC-MS/MS has been well validated in the United States"
Morning salivary cortisol is as good as serum as screening test for patients with Addison's disease and nighttime salivary cortisol is more adequate than serum in the screening of Cushing's syndrome.
Measurement of an elevated late-night (2300 to 2400 h) salivary cortisol has a greater than 90% sensitivity and specificity for the diagnosis of endogenous Cushing's syndrome
It is expected that the use of the measurement of salivary cortisol will become routine in the evaluation of patients with disorders of the HPA axis.
Late-night salivary cortisol measurement yields excellent overall diagnostic accuracy for Cushing's syndrome, with a sensitivity of 92-100% and a specificity of 93-100%