A case of normotensive primary aldosteronism-comparison with 13 previously experienced cases with hypertension.

Abstract

A 47-year-old woman with normotensive primary aldosteronism is reported. In this case, hypopotassemia was found, but the patient's blood pressure was within the normal range. Her condition was diagnosed as primary aldosteronism without hypertension, which is very rare, based on an increased level of plasma aldosterone concentration, low plasma renin activity, and a typical finding of aldosterone-producing adenoma by adrenal scintigraphy. In the present case, similar values for urinary volume, renal function, plasma aldosterone concentration, plasma renin activity, plasma volume, total exchangeable sodium, urinary kallikrein excretion and a similar weight of the resected adenoma, but a shorter duration between the onset of symptom and hospital admission were observed as compared with those in 13 previously experienced cases of primary aldosteronism with hypertension. Thus, a shorter duration of primary aldosteronism appears to be an important factor in explaining the mechanism of normotension. However, we were unable to reach a definite conclusion and this is only a hypothesis. Further investigation will be required to clarify the mechanism of normotension in primary aldosteronism.

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.…”

“…These results suggest that the variability of the pressure response to some agents cannot alone account for the normal blood pressure. Excessive production of vasodilators such as prostaglandin E and kallicrein is largely speculative (7,11,13).…”

“…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.…”