Corticosteroid dysfunction

Question 1

What are the causes of primary hyposecretion of glucocorticoids?

Answer 1

Addison’s disease, associated with decreased cortisol and aldosterone production
Insufficiency can also be caused by adrenal metastases, TB, meningococcal septicaemia, AIDS, congenital unresponsiveness to ACTH or enzyme deficits

Question 2

What are the causes of secondary hyposecretion of glucocorticoids?

Answer 2

Due to low ACTH levels (negative feedback on hypothalamic pituitary due to prolonged corticosteroid therapy/pituitary hypofunction)- need to increase dose
Inhibition of ACTH release by tranquilizers, morphine or antidepressants

Question 3

What are the clincial symptoms of Addisons?

Answer 3

Muscle weakness, postural hypotension, dehydration, salt craving, hypoglycaemia
Anorexia and decreased weight
Nausea and vomiting, diarrhoea, fever, abdominal pain
Tiredness and malaise
Low plasma cortisol and high ACTH levels

Question 4

What are the clinical symptoms of secondary adrenal insufficiency?

Answer 4

Low plasma cortisol and low ACTH levels

Increased skin pigmentation due to increased ACTH

Question 5

What is the diagnostic test for hyposecretion?

Answer 5

ACTH stimulation test- injection with synthetic ACTH fragment via IM or IV
Low plasma cortisol- indicates unresponsive adrenal cortex, primary adrenal insufficiency
High plasma cortisol- indicates unresponsive hypothalamic pituitary axis, secondary adrenal insufficiency

Question 6

What is the treatment for Addison’s disease?

Answer 6

Combination of oral replacement therapy with hydrocortisone 20-30 mg daily and fludrocortisone acetate 50-200 mcg daily
Dose determined by following various markers such as weight, BP, oedema, serum sodium and potassium concentrations and haematocrit
Life-long treatment, glucocorticoid dose is usually doubled to cope with stress e.g. infection, surgery

Question 7

What are the causes of hypersecretion of glucocorticoids/ primary aldosteronism?

Answer 7

Conn’s syndrome, bilateral adrenal hyperplasia or small tumour of zona glomerulosa

Question 8

What are the symptoms of primary/secondary aldosteronism?

Answer 8

Sodium and water retention, hypertension, hypokalaemia, muscle weakness, fatigue, cardiac dysrhythmias

Question 9

What is the diagnosis and treatment for primary aldosteronism?

Answer 9

Diagnosis- high plasma/ urine aldosterone, low plasma renin

Treatment- removal of tumour/ long term treatment with spironolactone

Question 10

What are the causes of secondary aldosteronism?

Answer 10

Abnormally high renin release
Caused by excessive sodium and water loss during diuretic therapy, poor renal perfusion, malignant hypertension, tumour of juxta-glomerular cells, dietary sodium reduction, congestive heart failure, renal cirrhosis

Question 11

What is the treatment for secondary aldosteronism?

Answer 11

Treat the underlying condition

Question 12

Reduced activity/ lack of 11-B hydroxysteroid dehydrogenase, cortisol exerts mineralocorticoid events:

Answer 12

Symptoms as with primary/secondary aldosteronism

Treatment: long term spironolactone therapy

Question 13

What enzymes are commonly missing in enzyme deficits?

Answer 13

3-B-hydroxysteroid dehydrogenase
21-B-hydroxylase
11-B-hydroxylase
17-a-hydroxylase (congenital)
corticosterone methyl oxidase

Question 14

What are the characteristics of enzyme deficits?

Answer 14

Associated with decreased cortisol and/or aldosterone, sometimes virilisation due to DHEA build up
Male sexual characteristics in female embryos and enhanced male sex characteristics
Treatment- glucocorticoid and/or mineralocorticoid replacement therapy for life