Hypertension and hypokalemia: unusual syndromes

Secondary hypertension accounts for a minority of all cases of hypertension. Certain clues in the patient's medical history and laboratory parameters may help identify the rare patient with secondary hypertension. The association of hypertension with hypokalemia and renal potassium wasting should raise one's suspicion for a state of mineralocorticoid excess. The clinical syndrome of hypertension and hypokalemia may be related either to a high renin state, such as renovascular disease, or to a low renin state, such as primary hyperaldosteronism, adrenal enzyme defects, certain familial syndromes, and licorice ingestion. Over the past decade, a genetic basis has been identified for apparent mineralocorticoid excess (AME) syndrome, Liddle's syndrome, and glucocorticoid remediable aldosteronism (GRA). This brief review focuses on a few of the unusual conditions which cause a true or apparent mineralocorticoid excess state, and summarizes the clinical presentation, pathogenetic mechanism, and treatment of these diseases.