• Primary aldosteronism:
  • Overview:
    • twice as common in women as in man
    • most often presents between 30 in 50 years of age
  • Most common cause:
    • adrenal adenoma -- excessive aldosterone production
      • unilateral adenoma (usually small; either side)
    • Conn's syndrome
  • Other causes:
    • hyperplastic adrenal glands -- abnormal secretion
    • malignant tumor
      • adrenal carcinoma (rare)

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  • Physiological Effects of aldosterone hypersecretion:
    • increased renal distal tubule or exchange of sodium for secreted potassium and hydrogen ions -- body potassium depletion/hypokalemia
  • Diagnosis--Criteria:
    1. diastolic hypertension (no edema)
    2. renin hyposecretion (low plasma renin activity)
       • renin secretion does not increase with volume depletion
    3. aldosterone hypersecretion that is not suppressed with volume expansion
  • Clinical Presentation:
    • diastolic hypertension (not very severe)
      • secondary to increase sodium reabsorption/volume expansion
    • headaches
    • polyuria, polydipsia
      • impairment of urinary concentrating ability
    • weakness
      • due to effects of potassium depletion
    • tetany
    • Electrocardiographic changes -- consistent with potassium depletion (hypokalemia-- which increases ectopy)
      • prominent U waves
      • cardiac arrhythmias
      • premature contractions
    • Many effects secondary to potassium loss associated with:
      • hypokalemia
        •  may be severe (< 3 mmol/L)
      • hypernatremia-- due to:
        • sodium retention
        • water loss from polyuria
      • metabolic alkalosis-- due to
        • urinary hydrogen ion loss
        • movement of hydrogen ion into potassium-depleted cells
        • alkalosis enhanced by potassium deficiency which increases proximal convoluted tubule capacity to reabsorb filtered bicarbonate.
  • Treatment:
    • Due to adenoma -- usually treated surgically
      • may be treated by:
        • sodium intake restriction
        • aldosterone antagonist (spironolactone (Aldactone))
          •  prolonged medical management (chronic therapy) may be side effect limited (males)
            1. gynecomastia
            2. decreased libido
            3. impotence
    • Due to idiopathic bilateral hyperplasia
      • symptomatic hypokalemia treated by:
        1. spironolactone (Aldactone)
        2. triamterene (Dyrenium)
        3. amiloride (Midamor)
      • surgery if pharmacological treatment fails
• Secondary aldosteronism:
  • Cause: appropriate increased aldosterone production due to renin-angiotensin system activation
  • Associated with:
    •  accelerated hypertension
    •  presence of edema disorder 
  • in pregnancy:
    • normal physiologic response to estrogen-induced increased plasma renin substrate and plasma renin activity and to antialdosterone actions of progestogens
  • in hypertension -- cause:
    • over production of renin (primary reninism)
    • renin over production secondary to reduced renal blood flow/perfusion pressure
      •  reduced renal artery lumen secondary to atherosclerosis or fiber muscular hyperplasia
    •  severe arteriolar nephrosclerosis (malignant hypertension)
    •  profound renal vasoconstriction (accelerated hypertension)
  • may be caused by rare renin-producing tumors (primary reninism)
    • juxtaglomerular cell tumor
  • Physiological characteristics:
    • increased plasma renin activity
    • moderate/marked increases in aldosterone levels
    • hypokalemic alkalosis

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