Adrenocortical hypofunction

Question 1

Adrenocortical hypofunction classifications

Answer 1

Primary, secondary, Addisons, Chronic adrenal insufficiency

Question 2

General information about primary adrenocortical hypofunction

Answer 2

Inability of the adrenals to elaborate sufficient amounts of hormone. Characterized by loss of all three types of adrenal steroids. Usually more than 90% of the gland must be destroyed in order to manifest clinically.

Question 3

Causes of primary AHF

Answer 3

Anatomic destruction of the gland: Autoimmune, adrenoleukodystrophy - X-linked inherited demyelinization due to a disease of VLFA metabolism.Gives progressive neurological symptoms as well. Hemorrhage - Waterhausen-Freidrichsen syndrome. Metastasis. Surgical.

Metabolic hormone production: Enzyme inhibitors, cytotoxic agents

Mutations in the ACTH receptor gene

ACTH blocking antibodies

Adrenal hypoplasia - congenital

Question 4

Clinical signs of primary AHF

Answer 4

Weakness, anorexia nausea and vomiting, cutaneous and mucosal pigmentation, hypotension (80/50 mmHg or less), hypoglycemia, abdominal pain, salt craving, diarrhea, constipation, syncope, vitiligo, sexual dysfunction, psychiatric manifestations

Question 5

Lab results in the case of primary AHF

Answer 5

Basal steroid output may be normal, but after stress it can be subnormal.
In the case of adrenal stimulation with ACTH - it leads tp subnormal increase in cortisol or none at all.
Serum values: Decreased - sodium loss leads to hypotension and fluid loss, decreased chloride and bicarbonate
Increased - Potassium due to aldosterone deficiency
Normocytic anemia may be present

Question 6

Treatment of primary AHF

Answer 6

Specific hormone replacement
Cortisol 20-30 mg/day, should be taken with meals (2/3 in the morning, 1/3 in the afternoon)
Fludrocortisone 0.05 - 0.1 mg/day
Special therapeutic problems: intercurrent illness such as fever, the dose of cortisol should be doubled. If there is a severe illness, the dose can be increased to 75mg - 150 mg/day
Fludrocortisone dose should be increased and add salt during periods of strenuous exercise, sweating, diarrhea.
Major surgery, major stress.

Question 7

General information about secondary adrenocortical hypofunction

Answer 7

Due to inadequate ACTH formation or release: can be because of hypopituitarism due to primary hypothalamic pituitary disease. Can be due to suppression of hypothalamic-pituitary axis by exogenous or endogenous hormones. Deficiency of glucocorticoids and adrenal androgens, but mineralocorticoids are unaffected.

Question 8

Causes of secondary AHF

Answer 8

Chronic exogenous glucocorticoids: suppresses the diurnal CRH/ACTH release. Reversible.
Postpartum necrosis of the pituitary - Sheehan syndrome.
Adenoma hemorrhage.
Pituitary destruction from head.

Question 9

Symptoms of secondary AHF

Answer 9

Same as in primary, except:

• ACTH is low, thus no hyper pigmentation, near normal aldosterone secretion
• May be hyponatremia

Question 10

Treatment of secondary AHF

Answer 10

Glucocorticoid supplementation (same as primary)
Mineralocorticoid treatment is not necessary - aldosterone is preserved.

Question 11

Addisons disease

Answer 11

Characterized by progressive destruction of the adrenals. Can be due to a chronic granulomatous disease (TBC, cryptococcosis), Idiopathic atrophy-autoimmune mechanism, ACTH receptor blocking antibodies, Type II polyglandular syndrome.
Rarely occurs due to adrenoleukodystrophy, hemorrhage, tumor metastasis.

Question 12

Chronic adrenal insufficiency

Answer 12

Clinically: Hyponatremia and hyperkalemia.

Only occurs in primary and is associated with azotemia and metabolic acidosis.