Disorders of Adrenocortical Function Flashcards
What does cortisol do?
Anti inflammatory and immunosuppressive
Increases Gluconeogenesis, lipolysis and proteolysis to maintain blood glucose for survival
Proteins are catabolised to release aa.s
Na+ and H2O retention maintains BP
Increases gastric acid production
Define Cushings syndrome and disease
Cushing’s Syndrome: excess cortisol in the blood
Cushing’s Disease: excess cortisol in the blood due to an ACTH secreting pituitary tumour
What are the clinical features of Cushings syndrome?
High blood pressure and fluid retention due to salt and water retention
Depression and anxiety
Irregular periods, erectile dysfunction in males
Redness of the cheeks (facial plethora), dark stretch marks
Central obesity
Hypokalaemia
Metabolic Alkalosis
Hyperglycaemia
Describe how Cushings disease is investigated
Screening:
Urinary free cortisol
Diurnal Rhythm
Overnight dexamethasone suppression test
Diagnosis confirmation:
Low dose Dexamethasone Suppression testing to see if cortisol levels come down. If it doesnt come down they have Cushings
How can you identify and localise the cause of the Cushings syndrome?
Pituitary: use MRI or inferior Petrosal sinus sampling IPSS
Adrenal: CT or MRI
Ectopic: octreotide Scan, ACTH Sampling
Describe the treatment of the various causes of Cushings disease
Adrenal adenoma: Surgery, cortisol Production Blockers is used beforehand
Adrenal cancer: radiotherapy and chemotherapy
Pituitary: Surgery and radiotherapy. Following treatment patients may require replacement of other pituitary hormones too
What are the clinical features of Addisons disease?
Tiredness Weakness Anorexia Weight loss Postural hypotension Hyponatraemia Hyperkalaemia Acidosis Basically the opp of cushings because it is due to a lack of cortisol
What are the main causes of Addisons disease?
Autoimmune
TB
Steroid Withdrawal
What is the first investigation for Addisons disease?
9 AM cortisol- when cortisol levels are supposed to be at their highest. If its low, addisons
ACTH: high levels show primary addisons
Adrenal imaging
Adrenal anti-bodies (see if autoimmune)
What further tests do you do for adrenal insufficiency in Addisons disease?
Short Synacthen: Give ACTH to stimulate adrenal directly, if still low, primary adrenal failure (Addison’s disease)
Long Synacthen Test: prolonged stimulation of adrenal using larger ACTCH dose. Diagnoses secondary adrenal failure (due to pituitary failure)
Insulin or glucagon tolerance test: stimulates the hypothalamus directly to asses adrenal axis
What is the treatment of Addisons disease/cortisol deficiency?
Hydrocortisone: Mimicks the diurnal rhythm. Last dose before 6pm bc cortisol is undetectable at night
Fludrocortisone: in primary adrenal failure to replace aldosterone
What is CAH?
Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders, HLA linked.
It results from the deficiency of one of the 5 enzymes required for cortisol synthesis in the adrenal cortex
Give the classical and non classical symptoms of CAH
Classical and non classical: Excess sex steroids cause
virilisation, premature puberty, infertility.
No aldosterone, hence salt-losing crisis: hyperkalaemia, hypotension.
In non classical only: No aldosterone but high DOC, which is an agonist at MC receptors: hypertension and hypokalaemia
What is the treatment of CAH?
Glucocorticoid replaces cortisol deficiency and suppresses pituitary ACTH production.
Glucocorticoid also reduces adrenal stimulation, reducing intermediate and sex steroid production.
Surgery to virilised female genitalia.
Treatment of mother to prevent foetal virilisation
What is the first type of aldosterone syndrome?
Primary Excess: High Aldosterone, Low Renin. Examples: Conn’s Syndrome Bilateral Adrenal Hyperplasia Aldosterone producing adrenal carcinoma
