Low-renin primary hypertension in a young patient treated with dexamethasone.

We have studied a young untreated patient with low-renin hypertension. All the clinical tests were in normal range, except plasma renin activity, which was low. Also all traditional tests evaluating the adrenal function were normal. A test of supraphysiological ACTH stimulation revealed a partial enzymatic defect of adrenal 11-hydroxylase. The patient has been treated with dexamethasone (0.75 mg once daily), during 4 weeks. At the end of the treatment blood pressure reached normal values. The traditional adrenal function tests are not sufficient to exclude enzymatic abnormalities and their possible involvement in the pathogenesis of hypertension.