Differentiation between subtypes of primary hyperaldosteronism by multiple steroid measurement after dexamethasone administration.

In 6 patients with primary hyperaldosteronism (P.H.) and a unilateral adrenal adenoma (A) and in 5 patients with P.H. obviously due to bilateral adrenal hyperplasia (H), multiple serum corticosteroids were measured after different dietary or drug regimens. After administration of dexamethasone on a normal sodium diet, serum levels of 11-deoxycorticosterone (DOC), corticosterone (B) and cortisol (F) were much lower in the H than in the A group. With respect to 11-deoxycorticosterone levels, there was no overlap between the two groups. Multiplication of individual serum DOC, B and F levels allowed a clearer separation of patients with A and H. This non-invasive method may offer an additional means in the differential diagnosis of P.H.