Establish the diagnosis of adrenocortical insufficiency, Addison’s disease, adrenocortical hypersecretion, Cushing’s syndrome. Malfunction of the organs in the hypothalamic-pituitary-adrenal cortex axis will result in alteration of the cortisol levels.
This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.
Limitations
Pregnancy, contraceptives, and estrogen therapy give rise to elevated cortisol concentrations.1 In samples from patients who have been treated with prednisolone, methylprednisolone, or prednisone, falsely elevated concentrations of cortisol may be determined.1 During metyrapone tests, 11-deoxycortisol levels are elevated.1 Falsely-elevated cortisol values may be determined due to cross reactions. Patients suffering from 21-hydroxylase-deficiency exhibit elevated 21-deoxycortisol levels and this can also give rise to elevated cortisol levels.1