|See Also||Lab Tests|
This test is used to diagnose hyperaldosteronism. A plasma renin assay may be conducted simultaneously, in order to differentiate primary aldosteronism (adrenal pathology) from secondary aldosteronism (extra-adrenal pathology).
- Aldosterone is a hormone produced by the adrenal cortex and its production is regulated by the renin-angiotensin system.
- Aldosterone is also stimulated by ACTH, low serum sodium levels, and high serum potassium levels.
- In turn, aldosterone stimulates the renal tubules of the kidney to absorb sodium and to secrete potassium in the urine, thereby regulating serum sodium and potassium levels.
- Aldosterone also partially regulates water absorption, since water follows sodium transport.
- No fasting required.
- Factors which can cause increased levels
- Strenuous exercise, stress
- Drugs: diazoxide (Hyperstat), hydralazine (Apresoline), nitroprusside (Nipride), diuretics, laxatives, potassium, and spironolactone.
- Factors which can cause decreased levels
- Excessive licorice ingestion
- Drugs: fludrocortisone (Florinef), propranolol (Inderal), and angiotensin-converting enzyme inhibitors (e.g. captopril), and licorice
High levels indicate:
- Aldosterone-producing adrenal adenoma (Conn disease)
- Adrenal cortical nodular hyperplasia
- Bartter's syndrome
- Diuretic ingestion resulting in hypovolemia and hyponatremia
- Laxative abuse
- Malignant hypertension
- Poor perfusion states (e.g. congestive heart failure)
- Decreased intravascular volume (e.g. cirrhosis, nephrotic syndrome)
- Renal arterial stenosis
- Pregnancy and oral contraception
- Hypovolemia or hemorrhage
- Cushing's disease
Low levels indicate:
- Aldosterone deficiency
- Renin deficiency
- Steroid therapy
- Addison's disease
- Patients on high-sodium diet
- Toxemia of pregnancy
- Antihypertensive therapy
- Serum Sodium, Sodium Urine Test, Serum Potassium, Potassium Urine Test, Adrenocorticotrophic Hormone (ACTH), Renin Assay
- Pagana Kathleen D, Pagana Timothy J (2006) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby.