Primary hyperaldosteronism

Causes

1. Adrenal adenoma (Conn's syndrome)
2. Bilateral adrenal hyperplasia
3. Adrenal carcinoma

Clinical suspicion

Indistiguishable from hypertension except that it occurs at an early age and usually is very high (malignant hypertension). It maybe accompanied by potassium depletion.

Diagnosis

Elevated plasma aldosterone level that is not suppressed with saline infusion or fludrocortisone adminstration.

Suppressed plasma renin activity. Plasma aldosterone/renin ratio exceeds 30.

Treatment

For adenoma the treatment is surgical removal. This leads to normalization of blood pressure in 70% of the cases. If the blood pressure is not controlled on spironolactone, it is unlikely to respond to surgery and such patients should be controlled by convetntional antihypertensives.

For hyperplasia, spironolactone 100-400mg daily or amiloride 10-40mg daily.

For glucocorticoid remidiable aldosteronism: dexamethasone 1-2mg/day. However, the response may dissipate over the long term and additional antihypertensives may be needed.