A case of normoreninemic, normotensive primary aldosteronism associated with essential hypertension and nephrocalcinosis.

A 36-year-old female case of normotensive normoreninemic primary aldosteronism with persistent hypokalemia and nephrocalcinosis is reported. She was referred to us for episodes of sudden muscle weakness during 8 years prior to admission. On the first day of admission, her blood pressure was 174/104 mmHg. On the second day of admission blood pressure normalized to 120/80 mmHg. Both of her parents were hypertensive. Arterial blood gas analysis showed metabolic alkalosis. Except an impaired urine concentration ability, renal functions were normal. Intravenous pyelogram showed numerous granular calcifications. Basal plasma renin activity was 1.0 approximately 1.5 ng/ml/hr and increased by sodium depletion. Plasma aldosterone concentration was 70 approximately 80 ng/dl and did not respond to various stimulations. Blood pressure was dependent on sodium balance. It fell on salt restriction and rose on salt loading. Blood pressure responses to vasoactive hormones were normal. Circulating plasma volume was within normal range. After removal of an adrenal adenoma, there was mild fall of blood pressure, serum potassium returned to normal level and plasma renin activity increased slightly. Histologically, there was renal tubular calcifications, and juxtaglomerular apparatus was normal. Blood pressure was elevated to 160/100 mmHg when patient was followed at out-patient clinic after discharge. We concluded that she had essential hypertension associated with primary aldosteronism. Although sodium loss and an increase in urinary kallikrein were found, they did not seem to be the cause of normoreninemic normotensive state of this patient, and the pathogenesis remains to be elucidated.