Asymptomatic normotensive primary aldosteronism. Case report.

Abstract

SUMMARY We report a case of primary aldosteronism in a 30-year-old woman without hypertension or any other characteristic symptoms. The condition was first suspected by hypokalemia (2.6 mEq/liter), which was incidentally found by routine checkup. There was evidence of suppressed plasma renin activity (PRA) and elevated plasma aldosterone levels. However, the blood pressure never reached a hypertensive level, and the circulating blood volume was within a normal range. A functioning right adrenal tumor was diagnosed by adrenal scintigraphy, computerized x-ray tomography, and adrenal venography. Adrenal venous catheterization suggested an aldosteronoma, which was confirmed by lateralized hypersecretion of aldosterone. After removal of the benign adenoma, the biochemical abnormalities were corrected, yet the blood pressure remained much the same. Hypertension is not necessarily a sign of primary aldosteronism. 1 There have also been cases with normokalemia.2 Although the hypertension is usually mild and may fluctuate, it is only recently that consistently normotensive cases of primary aldosteronism, due to adrenal adenoma 3 " 5 and idiopathic adrenal hyperplasia, 6 have been reported. All of the normotensive cases of aldosteronoma reported had been detected due to some symptoms related to hypokalemia. Herein, we report a case of aldosteronoma without hypertension which was first suspected because of persistent hypokalemia but revealed no symptoms characteristic of hypokalemia.

Aldosterone-producing adenoma without hypertension: a report of two cases

“…Only 16 cases of normotensive primary hyperaldosteronism have been reported in the literature, with only 10 in the English literature (5)(6)(7)(8)(9)(10)(11)(12)(13)(14). About 75% of cases were described in Eurasians (especially Japanese).…”

“…Arterial hypertension could be related to the early diagnosis of hyperaldosteronism (5,7,8,10,11). However, the 3-year history of hypokalemia in the first patient, and the second patient's blood pressure stability for more than one year before surgery despite hypokalemia, argue against this hypothesis.…”

“…It has been suggested that the absence of volemic expansion (8,10) or a low salt diet may account for the lack of arterial hypertension. However, hypervolemia is mainly responsible for the early increase in blood pressure and is then supplanted by other mechanisms.…”

“…In particular, hypokalemia is lacking in 7 to 38% of cases (3,4). In contrast, normotensive primary hyperaldosteronism is exceedingly rare: to the best of our knowledge, only ten cases have been documented (5)(6)(7)(8)(9)(10)(11)(12)(13)(14). We report two new cases studied by means of ambulatory blood pressure monitoring (ABPM).…”

Should primary aldosteronism be diagnosed among normotensive subjects during general health check-up and/or at general outpatient clinics?

“…There have been several case reports, describing PA without hypertension, [25][26][27][28][29][30][31] although the reason for the absence of hypertension has not been clarified in any of the cases of normotensive PA reported. It is suggested that a short duration of hyperaldosteronemia could explain normotension in those patients.…”