Analysis index

1 ml serum (stability in serum at 4° C – 8° C: 7 days)

Avoid stress. As far as clinically justified, discontinue glucocorticoids due to potentially severe cross-reactions (i.e. prednisolone 65 %).

Mornings: 3,7 – 19,4 µg/dl

Afternoons: 2,9 – 17,3 µg/dl

Nights: 0 – 10 µg/dl

Circadian rhythm with maximum values between 08:00 and 09:00 o’ clock and minimal values between 2300 hours and midnight.

Clarification of hirsutism, adiposity (including the preparation for bariatric surgery), unclear muscular weakness, unclear leukocytosis, suspicion of primary and secondary adrenal insufficiency

Basal cortisol values can anyhow only be used in the context of hypo- or hypercortisolism screening and are then only suitable if ACTH is evaluated simultaneously. The additionally collected ACTH sample however, has to be centrifuged and frozen at once. Saliva cortisol or a 24-hour urine for free cortisol can also be used as a screening method for hypercortisolism. A definite evaluation of both primary and secondary adrenal cortex insufficiency as well as hypercortisolism is only possible with function tests (such as ACTH stimulation test, dexamethasone suppression test). In case of increased cortisol levels, oral contraception must be ruled out as the cause.