Adrenal Disease

Question 1

What hormones are produced by the adrenals and in what areas anatomically?

Answer 1

Cortex (out to in):

Zona Glomerulosa: Mineralocorticoids - e.g. aldosterone

Zona Fasciculata: Glucocorticoids - e.g. cortisol

Zona Reticularis: Androgens - e.g. testosterone

Medulla

Catecholamines e.g. adrenaline

Question 2

Pro forma for Cushing’s exam?

Answer 2

WIPER - appearance, any suggestion of codition treated with long-term steroids

Hands - bruising, size, skin fold thickness

Arms - bruising, BP, shoulder AbD for prox myopathy

Face - ‘moon’ facies, greasy skin

Abdomen - purple striae, thin skin, ? renal Tx

Legs - stand from chair without using arms,

Back - spinal tender, interscapular fat pad

Finish by urine dip, BM

Question 3

What are some of the signs of Cushing’s?

How does this reflect the functions of the hormone?

Answer 3

S - spinal tenderness

W - weight gain, obesity

E - asy bruising

D - DM

I - interscapular fat pad

S - striae

H - hypertension

Glucocorticoid function - DM, glycosuria,

Mineralocorticoid - HTN, hypokalaemia

Catabolic - muscle wasting, OP, striae

Question 4

What investiagtions for Cushing’s?

Answer 4

1. 24h free urinary cortisol - time-consuming and dififcult
2. Loss of diurnal variation - should have lowest level at midnight, and peak at 9 am.
3. Low dose dexamethasone suppression - should suppress cortisol

Question 5

4 causes of Cushing’s

What is the difference between the disease and the syndrome?

Answer 5

1. Pituitary adenoma
2. Ectopic ACTH - e.g. paraneoplastic
3. Adrenal Tumour
4. Exogenous steroids

Cushing’s disease is caused by pituitary adenoma ONLY

All the rest are Cushing’s syndrome

Question 6

How can you differentiate between adrenal and pituitary Cushing’s?

Answer 6

ACTH Assay

ACTH levels elevated in pituitary

ACTH depressed in Cushing’s syndrome

Tricky assay

Question 7

Causes of adrenal insufficieny??

What other conditions is Addison’s associated with?

What condition is both secondary and primary assoc with?

Answer 7

Primary Adrenal insufficiency

• Autoimmune (Addison’s)
  
  • Assoc with other autoimmune disorders e.g. DM, Vitiligo
  • More common in Females
• TB

Secondary AI

• Suppression w/ exogenous glucocorticoids
• Hypo/Pit disease
• Pit. tumour
• Adrenal suppression following successful therapy of endogenous Cushing’s syndrome

SIADH

Question 8

What can precipitate adrenal crisis?

How manifest?

How manage?

Answer 8

Any stress - Infection, trauma,

Sharp withdrawal of long-term steroids

BP drop, hyponatraemia, hyperkalaemia, coma

ABCDE, Full bio and haem profile needed; IV steroids, fluids (saline becasue of sodium loss) and ? ABx

Question 9

Why raised K+ ?

Why decreased Na+?

Answer 9

Hypoaldosteronism - therefore reduced K+ secretion in urine (RTA type 4) with mild metabolic acidosis

1. Reduced aldosterone = reduced sodium reabsorption
2. Increased ADH - dilutional…

Loss of cortisol means loss of negative feedback on HPA access. This leads to increase in CRH which normally stimulates ACTH, but also may stim ADH secretion –> leads to water retention and dilutional hyponatraemia

ADH is ACTH secretagogue (i.e. stim ACTH secretion

Question 10

What are signs and symptoms of Addison’s?

Answer 10

Broad and non-specific

Lassitude

Abdo pain

Nausea

DIarrhoea

Postural hypotension

ACTH-related - skin pigmentation (buccal mucosa, palm creases)

Hypoglycaemia - because loss of insulin antagonism by cortisol

Question 11

What possible investigations for Adrenal insufficiency?

Answer 11

• 9am cortisol - will be low
• Then do short syacthen - synthetic ACTH, will improve cortisol levels if secondary AI (to pituitary problem)
• ACTH levels - low in secondary AI
• U+E - low Na+. high K+