Approach to the patient with hypertension, unexplained hypokalemia, and metabolic alkalosis

We present a patient with hypertension and hypokalemia secondary to an aldo sterone-producing adenoma that was renin responsive (APARR). We discussed t he sequential approach to the diagnosis of the different subtypes of primar y aldosteronism and confirmed the presence of an APARR, The most common cau se of primary aldosteronism is an aldosteronoma; functionally, these adenom as respond poorly to angiotensin II but show a brisk response to adrenocort icotropin hormone. They have a pattern of aldosterone level that declines i n parallel with cortisol levels. Our patient had an APARR, with an increase of aldosterone In the upright posture. The unusual physiologic response, i ncidence, and clinical characteristics of APARR are reviewed. (C) 2001 by t he National Kidney Foundation, Inc.