Adrenal insufficiency

Adrenal insufficiency is defined as a group of "conditions in which the production of adrenal corticosteroids falls below the requirement of the body. Adrenal insufficiency can be caused by defects in the adrenal glands, the pituitary gland, or the hypothalamus."

Classification

The following classification is from Robbins and Cotran.

Primary insufficiency

Loss of cortex

• Congenital adrenal hypoplasia
• Autoimmune adrenal insufficiency
• Infection (including Waterhouse-Friderichsen syndrome)

Metabolic failure of hormone production

• Congenital adrenal hyperplasia
• Drug and steroid-induced inhibition

Secondary insufficiency

Hypothalamic pituitary disease

Hypothalamic pituitary suppression

Diagnosis

The following is from a systematic review:

Accuracy of the cosyntropin stimulation test.

Setting	sensitivity	specificity
Primary adrenal insufficiency (250-µg cosyntropin test)	97%	95%
Secondary adrenal insufficiency (250-µg cosyntropin test)	57%	95%
Secondary adrenal insufficiency (1-µg cosyntropin test)	61%	95%
Notes: 1. An abnormal test is a cortisol level < 415 nmol/L 30-60 minutes after injection of cosyntropin. However, if secondary adrenal insufficiency is a consideration, then a cutoff of 500 to 600 nmol/L is needed for adequate sensitivity. 2. A basal cortisol level is not usually needed.