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Hyperaldosteronism
Aka: Hyperaldosteronism, Aldosteronism, Conn's Disease, Conn's Syndrome
- Epidemiology
- Represents under 1% of Hypertension Causes
- Peak age 30-50 years
- Most patients are women
- Pathophysiology
- Inappropriate Aldosterone Hypersecretion
- Primary Hyperaldosteronism (See Causes below)
- Increased aldosterone is initiating event
- Results in sodium retention and volume increase
- Renin decreases
- Secondary Hyperaldosteronism (See Causes below)
- Decreased circulating volume is initiating event
- Results in increased renin and aldosterone
- Results in sodium retention
- Physiologic response to Aldosterone Excess
- Increased renal distal tubular sodium reabsorption
- Increased total body sodium content
- Increased water retention
- Escape phenomenon
- Compensatory increased ANF secretion
- Hypertension may not be solely volume expansion
- Increased peripheral vascular resistance
- Hypokalemia: Potassium lost in distal renal tubule
- Alkalosis: Ammoniagenesis
- Hydrogen ion loss (avid sodium retention)
- Polyuria: Decreased renal concentrating ability
- Plasma renin suppressed
- Unresponsive to intravascular volume depletion
- Causes
- Primary Hyperaldosteronism (Conn's Disease)
- Solitary adrenal adenomas (80-90%)
- Bilateral adrenal hyperplasia (10-20%)
- Idiopathic Hyperaldosteronism
- Accounts for 50% of cases at some referral centers
- Adrenal Carcinoma (rare)
- Unilateral Adrenal Hyperplasia (very rare)
- Secondary Hyperaldosteronism
- Hypertensive States
- Primary Reninism (rare renin producing tumor)
- Secondary reninism due to decreased renal perfusion
- Edematous States
- Cirrhosis
- Nephrotic Syndrome
- Symptoms
- Often Asymptomatic
- Frontal Headache
- Muscle Weakness to flaccid paralysis (Hypokalemia)
- Polyuria and Polydipsia (carbohydrate intolerance)
- Signs
- Hypertension
- May be severe
- Rarely malignant
- Motor Exam with decreased Muscle Strength
- Labs
- Serum Electrolytes
- Serum Potassium decreased (Hypokalemia)
- Serum Sodium increased (Mild)
- Metabolic Alkalosis
- Morning Aldosterone to PRA ratio
- Ratio over 20-25 (esp if >100) suggests Hyperaldosteronism
- Aldosterone >15 ng/dl and plasma renin low
- Saline suppression
- IVF: 300-500 cc/hour for 4 hours
- Normal response
- Aldosterone usually under 0.28
- Renin usually suppressed
- Differential Diagnosis: Hypertension with Hypokalemia
- Cushing's Disease
- Low Aldosterone and Low Plasma Renin
- Renal Artery Stenosis or other renal cause
- High Aldosterone and High Plasma Renin
- Management
- Adrenal Adenoma
- Surgical excision
- Adrenal Hyperplasia
- First-Line Agents
- Spironolactone (Aldactone)
- Alternative agents if Gynecomastia develops on Spironolactone
- Eplerenone (Inspra)
- Amiloride (Midamor)
- Precautions
- Follow Serum Potassium and Serum Creatinine every 6 months with these agents