HYPERALDOSTERONISM   69A

A 42-year-old man presents for evaluation of newly diagnosed hypertension. He is currently taking no medications and offers no complaints. A careful review of systems reveals symptoms of fatigue; loss of stamina; and frequent urination, particularly at night. Physical examination is normal except for a blood pressure of 168/100 mm Hg. Serum electrolytes are sodium, 152 mEq/L; potassium, 3.2 mEq/L; bicarbonate, 32 mEq/L; and chloride, 112 mEq/L.

What are the salient features of this patient’s problem? How do you think through his problem?

Salient features: Hypertension, including diastolic blood pressure elevation; fatigue; polyuria; hypernatremia; hypokalemia; elevated serum bicarbonate

How to think through: A complete diagnostic workup for secondary causes of hypertension is not necessary for every new diagnosis of high blood pressure, nor would it be feasible given the prevalence of hypertension in the population. At the same time, secondary causes of hypertension, such as hyperaldosteronism, are underrecognized. What are the major factors that should trigger a workup for secondary hypertension? (Onset at age <50 years; symptoms suggestive of pheochromocytoma, including headache, sweating, or palpitations; hypertension refractory to three medications, one of which is a diuretic; physical examination findings such as abdominal bruit or a cushingoid appearance.) This patient’s age, his systolic blood pressure of greater than 160 mm Hg, and his diastolic pressure of 100 mm Hg are indications for investigation. Serum sodium and potassium levels were appropriately checked and suggest a hyperactive renin–angiotensin–aldosterone axis. How can the problem be localized? (By obtaining an aldosterone-to-plasma renin activity ratio. If an elevated ratio is found, the next step is to document increased aldosterone secretion with a 24-hour urine collection.) Are his fatigue, poor stamina, and nocturia potentially attributable to this problem? (Yes. These may be caused by the associated hypokalemia.) What are the two most likely causes of hyperaldosteronism? (Bilateral adrenal hyperplasia and unilateral adrenal adenoma [Conn syndrome].) How should he be treated? (An aldosterone blocking agent such as spironolactone or eplerenone.)

HYPERALDOSTERONISM   69B

What are the essentials of diagnosis and general considerations regarding hyperaldosteronism?

Essentials of Diagnosis

Hypertension that may be severe or drug resistant

Hypokalemia (in minority of patients) may cause polyuria, polydipsia, muscle weakness

Elevated plasma and urine aldosterone levels and low plasma renin level

General Considerations

Excessive aldosterone production which increases sodium retention and potassium excretion

Cardiovascular events are more prevalent in patients with hyperaldosteronism

Most commonly caused by bilateral adrenal hyperplasia and aldosterone-producing adrenal adenomas (Conn syndrome)

Screen patients for hyperaldosteronism if they have blood pressure over 160/100 mm Hg; drug-resistant hypertension; hypertension with hypokalemia; adrenal incidentaloma; a family history of hyperaldosteronism, early-onset hypertension, or stroke

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