Hyperaldosteronism

Question 1

What is the function of aldosterone?

Answer 1

• Aldosterone is the main mineralocorticoid hormone
• It is a steroid hormone produced by the zona glomerulosa of the adrenal cortex in the adrenal gland.
• It is essential for sodium conservation in the kidney, salivary glands, sweat glands and colon.

Question 2

Describe the regulation and secretion of aldosterone

Answer 2

Question 3

What is primary aldosteronism?

Answer 3

• Excess production of aldosterone independent of RAAS
• it causes increase sodium and water retention and decreased renin release

Question 4

What are the symptoms of primary hyperaldosteronism?

Answer 4

• Asymptomatic
• Signs of hypokalaemia
  
  • Weakness
  • Cramps
  • Parasthesia
  • Polyuria
  • Polydipsia
  • Increased BP (but not always)

Question 5

What signs would make you consider primary hyperaldosteronism in a patient?

Answer 5

• Hypertension
• Hypokalaemia
• Alkalosis
• Hypernatraemia (or normal sodium)

All without diuretic use

Question 6

What are the causes of primary hyperaldosteronism?

Answer 6

• Solitary aldosterone producing adenoma
  
  • CONN’S SYNDROME
• Bilateral adrenocortical hyperplasia
• Rarer causes:
  
  • Adrenal carcinoma
  • Glucocorticoid remediable aldosteronism

Question 7

What tests are carried out to investigate primary hyperaldosteronism?

Answer 7

• U&Es
• Renin
• Aldosterone
• Adrenal vein sampling
• Do not rely on low potassium as 20% have normal levels
• For GRA (glucocorticoid remediable aldosteronism)
  
  • Family history of early hypertension

Question 8

How is primary hyperaldosteronism treated?

Answer 8

• Conn’s
  
  • Laprascopic adrenalectomy
  • Spironolactone for 4 weeks pre op controls BP and K levels
• Hyperplasia
  
  • Spironolactone
  • Amiloride
• GRA
  
  • Dexamethasone
    
    • 4 week treatment
    • This normalises biochemistry but not always BP
    • If BP is still high, use spironolactone as an alternative
• Adrenal carcinoma
  
  • Surgery and post op adrenolytic therapy with mitotane
  • The prognosis is poor

Question 9

What is secondary hyperaldosteronism?

Answer 9

High aldosterone due to high renin from decreased renal perfusion

Question 10

What are the main causes of secondary hyperaldosteronism?

Answer 10

• Renal artery stenosis
• Accelerated hypertension
• Hepatic failure
• Congestive heart failure
• Diuretics

Question 11

What is Bartter’s syndrome?

Answer 11

• An autosomal recessive congenital condition that cuases mutations in Loop of Henle channels and transporters
• The mutation causes a sodium and chloride leak and thus salt wasting
• The sodium loss leads to volume depletion, which activates RAAS and thus leads to increase in renin and aldosterone production
• This leads to:
  
  • Hypokalaemia and metabolic alkalosis
  • Increase in urinary K+ and Cl-

Question 12

How does Bartter’s syndrome present?

Answer 12

• It presents in childhood
  
  • Failure to thrive
• Polyruria
• Polydipsia
• BP is normal
• Hypokalaemia and metabolic alkalosis
• Increased urinary K+ and Cl-

Question 13

How is Bartters syndrome treated?

Answer 13

• Potassium replacement
• NSAIDs to inhibit prostaglandins
• ACEi

Question 14

What associations should make you think about Conn’s syndrome?

Answer 14

• Hypertensiona nd hypokalaemia
• Refractory hypertension (despite more than 3 antihypertensive drugs)
• Hypertension occuring beofore 40years of age (especially in women)