Selective Aldosterone Deficiency¹

Selective aldosterone deficiency is a rarely described entity, characterized by relative or absolute deficiency of aldosterone secretion and an otherwise normal adrenal function. An elderly Negro male with such a deficiency is described; the findings are compared with those of previously reported cases. The evidence is in favor of an acquired defect of the C-18 hydroxylating enzyme, the pathogenesis of which is unknown. In this entity the characteristic biochemical abnormality is hyperkalemia, at times of severe degree. Hyperkalemia is responsible for the observed clinical picture (cardiac arrhythmias and muscular paralysis). It arises and/or becomes more severe with depletion of body sodium, through a renal retention mechanism. It is corrected by small doses of salt-active steroid. In this patient occurrence of congestive heart failure, normal serum sodium and balance studies suggest adequate Na conservation, even when the intake is markedly restricted. In the other 6 cases thus far reported, the evidence is in favor of adequate sodium conservation. With the exception of the youngest patient of this series, Na balance during sodium deprivation was probably achieved by them also. Since renal function was normal, other unknown factors must be invoked to explain the ability to save sodium. Selective aldosterone deficiency should be considered in the differential diagnosis of hyperkalemia. Therapeutic management of this entity requires unrestricted Na diet, a salt-active steroid to forestall onset of hyperkalemia and, in case of congestive heart failure, cautious use of diuretics.