Girish Mahajan (Editor)

Hypoaldosteronism

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Specialty
  
Endocrinology

DiseasesDB
  
20960

ICD-10
  
E27.4

MeSH
  
D006994

Hypoaldosteronism

In medicine (endocrinology), hypoaldosteronism refers to decreased levels of the hormone aldosterone.

Contents

Isolated hypoaldosteronism is the condition of having lowered aldosterone without corresponding changes in cortisol. (The two hormones are both produced by the adrenals.)

Causes

There are several causes for this condition, including adrenal insufficiency, congenital adrenal hyperplasia, and medications (certain diuretics, NSAIDs, and ACE inhibitors).

  • Primary Aldosterone deficiency
    1. Primary adrenal insufficiency
    2. Congenital adrenal hyperplasia (21 and 11β but not 17)
    3. Aldosterone synthase deficiency
  • Secondary Aldosterone deficiency
    1. Secondary adrenal insufficiency
    2. Diseases of the pituitary or hypothalmus
  • Hyporeninemic hypoaldosteronism (due to decreased angiotensin 2 production as well as intra-adrenal dysfunction)
    1. Renal dysfunction-most commonly diabetic nephropathy
    2. NSAIDs
    3. Ciclosporin

    Treatment

  • Aldosterone deficiency should be treated with a mineralocorticoid (such as fludrocortisone), as well as possibly a glucocorticoid for cortisol deficiency, if present.
  • Hyporeninemic hypoaldosteronism is amenable to fludrocortisone treatment, but the accompanying hypertension and edema can prove a problem in these patients, so often a diuretic (such as the thiazide diuretic, bendrofluazide,or a loop diuretic, such as furosemide) is used to control the hyperkalemia.

    • Effects

    This condition may result in hyperkalemia, when it is sometimes termed 'type 4 renal tubular acidosis' even though it doesn't actually cause acidosis. It can also cause urinary sodium wasting, leading to volume depletion and hypotension.

    When adrenal insufficiency develops rapidly, the amount of Na+ lost from the extracellular fluid exceeds the amount excreted in the urine, indicating that Na+ also must be entering cells. When the posterior pituitary is intact, salt loss exceeds water loss, and the plasma Na+ falls. However, the plasma volume also is reduced, resulting in hypotension, circulatory insufficiency, and, eventually, fatal shock. These changes can be prevented to a degree by increasing the dietary NaCl intake. Rats survive indefinitely on extra salt alone, but in dogs and most humans, the amount of supplementary salt needed is so large that it is almost impossible to prevent eventual collapse and death unless mineralocorticoid treatment is also instituted.

    References

    Hypoaldosteronism Wikipedia
    (Text) CC BY-SA