Hyperaldosteronism + Conns

Question 1

Definition of hyperaldosteronism

Answer 1

Excess levels of aldosterone. The causes for this can be primary (independent of RAAS) or secondary (dependent on RAAS)

Question 2

What does Conn’s syndrome refer to?

Answer 2

primary hyperaldosteronism.

Results in increased sodium and thus water retention (resulting in increased BP).

Question 3

Epidemiology of hyperaldosteronism

Answer 3

• Primary hyperaldosteronism was originally thought to be rare, with a prevalence of <1%, but recent evidence suggests that it may be more common than initially thought.
• Common in middle-aged adults

Question 4

Aetiology of primary hyperaldosteronism

Answer 4

Describes adrenal dysfunction causing raised aldosteronelevels withdecreased reninlevels due to negative feedback from sodium retention. Causes include:

• Adrenal hyperplasia: idiopathic bilateral hyperplasia is the most common cause (⅔), can also be unilateral
• Adrenal adenoma: classically termedConn’s syndrome
• Adrenal carcinoma: extremely rare
• Familial hyperaldosteronism: rare

Question 5

Secondary hyperaldosteronsim aetiology

Answer 5

Describes inappropriate activation of the RAAS, therefore patients haveraised aldosterone and raised reninlevels. Causes include:

• Renal artery stenosis
• Heart Failure: arterial hypovolemia due to reduced oncotic pressure causes reduced renal perfusion

Question 6

RF

Answer 6

• Family history of early onset hypertension
• Family history of primary hyperaldosteronism

Question 7

Pathophysiology

Answer 7

Aldosterone is a mineralocorticoid and its role involves renal excretion of potassium and acid, as well as sodium reabsorption.

renin-angiotensin-aldosterone system (RAS) is activated in cases of hypovolemia and hyponatraemiaand leads to increased aldosterone levels with subsequent salt and water retention.

Classically, the disease presents as refractory hypertension, hypokalaemia, and metabolic alkalosis. Hypernatraemia may or may not be seen.

Question 8

Signs of HA

Answer 8

• Refractory hypertension
• Hypokalaemia - increased K+ secretion by kidneys
• Metabolic alkalosis - increased H+ secretion by kidneys

Question 9

Symptoms

Answer 9

• Lethargy
• Mood disturbance
• Paresthesia
• Muscle cramps
• Polyuria and nocturia

Question 10

1st line investigation for HA

Answer 10

Aldosterone/renin ratio: first-line diagnostic test. Will show high aldosterone, with low renin in cases of primary hyperaldosteronism and high aldosterone and high renin in cases of secondary hyperaldosteronism.

CT imaging should be performed if there is a raised ratio.

Question 11

Other Investigations

Answer 11

Serum U&Es
Blood gas
High res CT abdomen
Adrenal venous sampling

Question 12

Differential diagnosis

Answer 12

• Other forms of hypertension e.g.
  
  • Essential hypertension
  • Secondary hypertension
  • Liddle syndrome

Question 13

1st line management

Answer 13

• Laparoscopic adrenalectomy:forunilateraladrenal hyperplasia or adenoma
• Spironolactone:forbilateraladrenal hyperplasia or adenoma; spironolactone is an aldosterone antagonist

Question 14

2nd line management

Answer 14

• In unilateral disease where surgery is inappropriate, treat with spironolactone
• ENaC inhibitor: Amiloride, a potassium-sparing diuretic, may be used if aldosterone antagonists are not tolerated.

Question 15

Complications

Answer 15

• Secondary to long-standing hypertension:
  ischaemic heart disease
  stroke
  hypertensive nephropathy
  chronic kidney disease
• Iatrogenic - hyperkalaemia

Question 16

Prognosis

Answer 16

Patients with primary hyperaldosteronism have increased mortality and cardiovascular morbidity compared to age and sex-matched controls. Surgical management leads to a cure in 50% of patients and the rest will have improvement of symptoms and blood pressure.