Adrenal insufficiency

Addison’s disease is an endocrine disease that results from hypocortisolism caused by adrenal gland insufficiency. 

Adrenal insufficiency is significant because it is correlated with decreased ability to maintain blood pressure and blood sugar, a defect that can prove to be fatal.

Addison’s disease results from damage to the adrenal cortex.

An endocrine or hormonal disorder that occurs in all age groups and afflicts men and women equally.

Characterized by weight loss, muscle weakness, fatigue, low blood pressure, and sometimes darkening of the skin in both exposed and nonexposed parts of the body.

Damage to the adrenal cortex may be immune mediated, related to infections with tuberculosis, HIV, fungal infections, hemorrhage, malignancy and use of anticoagulants.

Associated with hypotension, diarrhea, tachycardia, darkening of the skin, extreme weakness, loss of appetite, buccal mucosal lesions, nausea and vomiting, salt craving, slow movement and unintentional weight loss.

Laboratory tests that may be abnormal include: elevated potassium, low sodium, and low cortisol levels.

Treatment with replacement corticosteroids will control the symptoms of this disease.

Corticosteroids usually need to taken for life.

People often receive a combination of glucocorticoids (cortisone or hydrocortisone) and mineralocorticoids (fludrocortisone).

Refers to decreased cortisol production and is confirmed by biochemical testing.

Aldosterone production is low in primary adrenal insufficiency and normal in secondary disease.

During critical illness an increase in circulating and tissue corticosteroids levels are required for adaptive responses.

With severe illness and stress the hypothalamic-pituitary-adrenal (HPA) axis is stimulated, with release of corticotropin releasing hormone (CRH) from the hypothalamus.

Corticotropin releasing hormone stimulates the anterior pituitary to release adrenocorticotropic hormone (ACTH), with ACTH causing increased cortisol production by the adrenal cortex zona fasciculata.

Pigmentary changes often seen in hands and other skin folds is related to coexpression of melanocyte stimulating hormone and corticotropin secreted from the pituitary gland

In acute illness like sepsis, trauma, and burns cortisol production by the adrenal gland is increased by as many as six fold.

Normally bound to corticosteroid-binding globulin with less than 10% free cortisol bioavailable form.

During acute illness cortisol-binding globulin levels decrease by 50% and unbound cortisol levels increases.

Secondary adrenal insufficiency occurs when the pituitary gland fails to produce an adequate amount of corticotropin, a hormone that stimulates the adrenal glands to produce cortisol.

Secondary adrenal insufficiency is much more common than Addison’s disease.