Primary Aldosteronism

Question 1

What is primary aldosteronism?

Answer 1

• Excess of aldosterone levels independant of the RAAS axis

Question 2

What are the hallmarks of PA?

Answer 2

• HTN
• Hypokalaemia (though often absent)
• Metabolic alkalosis

Question 3

What does PA commonly cause?

Answer 3

• Secondary HTN

Question 4

What are the causes of PA?

Answer 4

• idiopathic Adrenal Hyperplasia (most common)
  
  • normally bilatera
• Adrenal adenoma (Conn’s syndrome)
• Familiam hyperaldosteronism
• Adrenal carcinoma

Question 5

What are the 3 layers of the adrenal cortex and what hormones do they secrete?

Answer 5

• Zona Glomerulosa
  
  • Mineralcorticoid - Aldosterone
• Zona Fasciculata
  
  • Glucocorticoid - Corticosteroid
• Zona Reticularis
  
  • Androgen - DHEA

Question 6

What hormones does the adrenal medulla secrete?

Answer 6

• Adrenaline
• Noradrenaline
• Dopamine

Question 7

What cell secretes renin?

Answer 7

• Granular cells in juxtaglomerular apparatus

Question 8

Renin will be secreted in response to what?

*remember 3 things

Answer 8

• Renal artery hypotension
• Sympathetic stimulation
• Reduced Na levels at DCT

Question 9

What are the function of angiotensin II?

Answer 9

• Stimulates adrenal cortex to release aldosterone
• Causes vasoconstriction
• Increases sodium reabsorption
• Stimulates the release of anti-diuretic hormone (ADH)
• Increases sympathetic permissiveness

Question 10

Aldosterone will be released in response to?

*think 3 things

Answer 10

• Angiotensin II (primary stimulus)
• ACTH
• Potassium levels

Question 11

What is the primary action of Angiotensin II?

Answer 11

• Increase Na channels at DCT

Question 12

What are the clincal features of PA?

* think in the context of HTN & hypokalaemia

Answer 12

• HTN
  
  • Asymptomatic (majority)
  • If long lasting
    
    • CKD
    • CVD
    • HF
    • Retinopathy
• Hypokalaemia
  
  • Asymptomatic
  • Muscle weakness
  • Paresthesia
  • Mood disturbance
  • Polyuria

Question 13

What patients should be screened for PA?

Answer 13

• Hypertension and hypokalaemia
• Severe hypertension (systolic > 150, diastolic > 100)
• Hypertension resistant to treatment
• Hypertension and:
  
  • Adrenal incidentaloma
  • Sleep apnea
  • Family history of early onset hypertension
  • Family history of early onset CVA
  • Primary aldosteronism affecting all 1st degree relatives with hypertension

Question 14

How would you diagnose PA?

*multi tier testing approach

Answer 14

1. Screen suspected pt - ARR test
2. Confirmatory test
   
   • Oral sodium loading test - aldosterone suppression test
3. Identify the test
   
   • CT adrenal glands
   • Adrenal vein sampling (gold standard)

Question 15

What are the limitations of CT adrenal glands?

Answer 15

• difficult to distinguish adenomas from non-functioning incidentaloma

Question 16

How would you mx PA?

Answer 16

• unilateral
  
  • lap/open adrealectomy
• bilateral
  
  • Spironolactone, Eplerenone (newer, unlike spironolactone does not cause gynaecomastia)
  • Amiloride - if aldosterone antagonist not tolerated

Question 17

What are the SE of Spironolactone?

Answer 17

• Gynaecomastia
• nausea
• rashes