Hyperaldosteronism

From Anvita Health Wiki

Contents 1 More Specific Terms 2 Introduction 3 Etiology 4 Clinical-manifestations 5 Laboratory 6 Diagnostic-procedures 7 Radiology 8 Management 9 More General Terms 10 Additional Terms 11 References

More Specific Terms

• primary hyperaldosteronism (Conn's syndrome)

Introduction

• Excessive secretion of aldosterone:

Etiology

• primary hyperaldosteronism

• aldosterone-producing adrenal adenoma
• bilateral adrenal cortical hyperplasia

• glucocorticoid-remediable hyperaldosteronism

• 11-beta hydroxysteroid dehydrogenase deficiency

• criteria for diagnosis

• diastolic hypertension without edema
• hyposecretion of renin that fails to increase during volume depletion (upright posture, sodium depletion)
• hypersecretion of aldosterone that does not suppress appropriately with volume expansion (salt loading)

• secondary hyperaldosteronism

• aldosterone often higher than in primary hyperaldosteronism
• overproduction of renin

• primary reninism

• renin-producing juxtaglomerular cell tumor
• renin-producing tumors may also arise from the ovary
• Bartter's syndrome

• decrease in renal blood flow
• atherosclerosis
• fibromuscular dysplasia
• arteriolar nephrosclerosis

• increased circulating levels of renin substrate (angiotensin-1) in pregnancy
• licorice abuse

Clinical-manifestations

• mild to moderate diastolic hypertension
• headaches
• polyuria
• muscle weakness
• fatigue
• edema may occur with secondary hyperaldosteronism

Laboratory

• hypokalemia
• hypernatremia
• ABG may show metabolic alkalosis
• urinalysis

• pH neutral to alkaline
• specific gravity low
• urine K+ in a patient with hypokalemia indicates renal K+ losing state
• urine Cl- often elevated
• after a 3 day high salt diet

• 24 hour urine collection
• measure Na+, K+, creatinine & aldosterone
• aldosterone > 12 ug & urine Na+ > 200 meq/24 hr confirms diagnosis of hyperaldosteronism

• plasma aldosterone elevated relative to plasma renin

• aldosterone/ renin > 20 suggests primary hyperaldosteronism
• aldosterone/ renin < 10 suggests secondary hyperaldosteronism
• selective venous sampling may help localize tumor
• aldosterone ( ng/dL)/renin (mg/ mL/ hr) > 100 may have 100% predictive value [4]

• autonomy of aldosterone:

• salt loading fails to suppress aldosterone secretion
• captopril suppression test

• cortisol normal

Diagnostic-procedures

• electrocardiogram:

• left ventricular hypertrophy
• signs of hypokalemia

• prolongation of ST segment
• U waves
• T-wave inversions

Radiology

• CT scan may demonstrate adrenal mass
• iodocholesterol scan may be useful

Management

• surgical excision of adrenal aldosterone producing tumor
• unilateral or bilateral adrenalectomy seldom cures hypertension in cases of bilateral adrenal hyperplasia
• aldosterone antagonists

• spironolactone 25-100 mg every 8 hours
• triamterene
• amiloride

• dietary sodium restriction
• glucocorticoid-remediable hyperaldosteronism

• dexamethasone has less mineralocorticoid activity than cortisol

More General Terms

• syndrome
• endocrine disease
• mineralocorticoid excess

Additional Terms

• Bartter syndrome
• Glycyrrhiza glabra (licorice)
• hypokalemia
• Liddle's syndrome (pseudohyperaldosteronism)
• mineralocorticoid excess

References

1. Harrison's Principles of Internal Medicine, 13th ed. Companion Handbook, Isselbacher et al (eds), McGraw-Hill Inc. NY, 1995, pg 1965-68
2. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 227-29, 481-82
3. Medical Knowledge Self Assessment Program (MKSAP) 11, American College of Physicians, Philadelphia 1998
4. Journal Watch 21(10):78, 2001 Gallay BJ et al, Am J Kidney Dis 37:699, 2001

hyperaldosteronism