[Selective hypoaldosteronism with hyperkalemia. Clinical and physiopathological study of 22 cases with hypo- or...

Twenty-two patients with selective hypoaldosteronism (SH) were studied. In 18 of them decreased levels of plasma renin activity (PRA) were associated with the syndrome: 12 patients showed the idiopathic form of SH, while in 6, the syndrome was attributable to the administration of non-steroid anti-inflammatory drugs. In the remaining 4 patients, the hypoaldosteronism was characterized by associated increased PRA levels but functional studies excluded a diagnosis of adrenocortical insufficiency. From a critical review of the literature and from the present observations it seems likely that SH is a syndrome with a heterogeneous pathogenesis. The possibility exists that the major alterations in potassium homeostasis that characterize the syndrome of SH, though mainly attributable to deficiency of aldosterone secretion may actually depend on the concurrence of underlying mechanisms, in particular on the presence of distal nephron dysfunctions.