Abstract
Primary adrenal insufficiency (AI) is an endocrine disorder in which hormones of
the adrenal cortex are produced to an insufficient extent. Since receptors for
adrenal steroids have a wide distribution, initial symptoms may be nonspecific.
In particular, the lack of glucocorticoids can quickly lead to a
life-threatening adrenal crisis. Therefore, current guidelines suggest applying
a low threshold for testing and to rule out AI not before serum cortisol
concentrations are higher than 500 nmol/l (18 μg/dl). To
ease the diagnostic, determination of morning cortisol concentrations is
increasingly used for making a diagnosis whereby values of>350
nmol/l are considered to safely rule out Addison’s disease.
Also, elevated corticotropin concentrations (>300 pg/ml) are
indicative of primary AI when cortisol levels are below 140 nmol/l (5
μg/dl). However, approximately 10 percent of our patients with
the final diagnosis of primary adrenal insufficiency would clearly have been
missed for they presented with normal cortisol concentrations. Here, we present
five such cases to support the view that normal to high basal concentrations of
cortisol in the presence of clearly elevated corticotropin are indicative of
primary adrenal insufficiency when the case history is suggestive of
Addison’s disease. In all cases, treatment with hydrocortisone had been
started, after which the symptoms improved. Moreover, autoantibodies to the
adrenal cortex had been present and all patients underwent a structured national
education program to ensure that self-monitored dose adjustments could be made
as needed.
Key words
adrenal insufficiency - hyponatremia - glucocorticoid - aldosterone - adrenal crisis
