Body elemental composition, with particular reference to total and exchangeable sodium and potassium and total...

The whole body content of sodium, potassium, chlorine, calcium, phosphorus and nitrogen was measured by neutron activation analysis in 13 patients with untreated primary hyperaldosteronism (Conn's syndrome; aldosterone-secreting adenoma). Concurrently, exchangeable sodium and potassium were estimated by isotope dilution. Results were compared with values in the same patients during treatment with potassium-conserving diuretics and again after removal of the adenoma; and also with those in a series of 30 patients having untreated essential hypertension. Both total body and exchangeable sodium were high in Conn's syndrome before treatment and were reduced by spironolactone or amiloride and by subsequent surgery. There was no evidence of alteration in the proportion of non-exchangeable sodium in this disease, in contrast to earlier reports. Total body and exchangeable potassium were low in untreated Conn's syndrome and increased to normal after therapy: the proportion of non-exchangeable potassium was similar before and after treatment, and also similar to that in essential hypertension. Total body chlorine was increased before treatment in Conn's syndrome and returned to normal with therapy; body calcium, phosphorus and nitrogen were normal throughout.