Endocrine arterial hypertension: diagnostic approach in clinical practice.

Endocrine arterial hypertension (EAH) a condition in which hormone excess results in clinically significant hypertension is a rare cause of hypertension. However in the last years its prevalence has increased, mostly due to the improvement of diagnostic work-up. In clinical practice, hypertensive subjects with suspicion of EAH currently undergo hormonal screening of the renin-aldosterone and catecholamines and glucocorticoids excess. This paper reviews current understanding for earlier recognition of the main forms of EAH and discusses screening laboratory methods and localization techniques that have enhanced the clinician's ability to make the diagnosis of EAH. Primary aldosteronism (PA) has recently been recognised as the most frequent cause of EAH. The aldosterone to renin ratio (ARR) is a highly recommended screening test for PA. When ARR is increased, confirmatory tests as saline infusion or fludrocortisone suppression are required. Differential diagnosis of PA requires adrenal gland imaging by computed tomography (CT) or magnetic resonance imaging (MRI), biochemical testing of the aldosterone response to posture, and selective adrenal venous sampling to differentiate unilateral aldosterone-producing adenoma from bilateral hyperplasia. Hypertension is frequently found in endogenous Cushing's Syndrome (CS). Twenty-four-hour urinary free cortisol measurement is the gold standard for the diagnosis of CS, but it must be confirmed by the overnight dexamethasone suppression test. CT and MRI are the primary imaging studies to perform, while scintigraphy is a useful confirmatory method. The most specific and sensitive diagnostic test for catecholamine-producing neoplasms is determination of urinary metanephrine levels; the neoplasms can be located by CT, MRI and metaiodo-benzylguanidine scintigraphy.