Long-term re-evaluation of primary aldosteronism after medical treatment reveals high proportion of normal mineralocorticoid secretion

Objective: In most cases of primary aldosteronism (PA), an adrenal aldosterone-secreting tumor cannot be reasonably proven, so these patients undergo medical treatment. Controversial data exist about the evolution of PA after medical therapy: long-term treatment with mineralocorticoid antagonists has been reported to normalize aldosterone levels but other authors failed to find remission of mineralocorticoid hypersecretion. Thus, we planned to retest aldosterone secretion in patients with medically treated PA diagnosed at least 3 years before. Design: Retrospective, cross-sectional study. Methods: The same workup for PA as at diagnosis (basal aldosterone to renin activity ratio (ARR) and aldosterone suppression test) was performed after stopping interfering drugs and low-salt diet, in 34 subjects with PA diagnosed between 3 and 15 years earlier, by case finding from subgroups of hypertensive patients at high risk for PA. Criteria for persistence of PA were the same as at diagnosis (ARR (pg/ml per ng per ml per h) > 400, aldosterone > 150 pg/ml basally, and > 100 pg/ml after saline infusion) or less restrictive. Results: PA was not confirmed in 26 (76%) of the patients and also not in 20 (59%) using the least restrictive criteria suggested by international guidelines. Unconfirmed PA was positively associated with female sex, higher potassium levels, longer duration of hypertension, and follow-up, but not with adrenal mass, aldosterone levels at diagnosis, and treatment with mineralocorticoid antagonists. Conclusions: This study suggests that mineralocorticoid hyperfunction in patients with PA after medical treatment may decline spontaneously. Higher potassium concentration and duration of treatment seem to increase the probability of this event. European Journal of Endocrinology 168 525-532