insufficient aldosterone and cortisone

demographics

women, 30-50

aetiology

• Primary Adrenal Insufficiency: destruction of adrenal cortex
• Secondary Adrenal Insufficiency: conditions that decrease ACTH production
• Tertiary Adrenal Insufficiency: conditions that decrease CRH production

pathophysiology

• Addison’s Disease: autoimmune (idiopathic) damage to the adrenal gland leads to deficiency in all three hormones produced by the adrenal cortex: androgens, cortisol, aldosterone
  • Hypoandrogenism: loss of libido, impaired spermatogenesis
  • Hypocortisolism leads to:
    • increased ACTH → increased POMC production → increased MSH → bronze skin
    • increased ADH → retention of free water → dilutional hyponatremia
    • decreased expression of enzymes in gluconeogenesis → hypoglycaemia
    • Lack of potentiation of catecholamines → hypotension
  • Hypoaldosteronism → hypotension (hypotonic hyponatremia and volume contraction), hyperkalaemia, metabolic acidosis
• Secondary Adrenal Insufficiency: deccreased ACTH → hypoandrogenism and hypocortisolism (aldosterone synthesis not affected as its production is dependent on RAAS and Angiotensin II, not by ACTH)
• Tertiary Adrenal Insufficiency: decreased CRH → decreased ACTH → hypoandrogenism and hypocortisolism (aldosterone not affected)

risk factors

• Type I diabetes
• Hypoparathyroidism
• Hypopituitarism