Hyperaldosteronism: Screening and Diagnostic Tests.

Primary aldosteronism (PA) is the most common secondary cause of hypertension, accounting for 10 % of hypertensives and 20 % of those with drug-resistant hypertension. Aldosterone excess is associated with the development of adverse cardiovascular, renal and metabolic effects that are partly independent of its effect on blood pressure. Guidelines recommended wider screening for PA in an effort to maximize detection of patients who may benefit from optimal, specific management. All patient groups with increased prevalence of PA, including hypertensive patients with type 2 diabetes mellitus and those with obstructive sleep apnea, should be carefully screened for PA. Screening with aldosterone-to-renin ratio (ARR) is the most practical and informative initial test. Subsequent confirmatory tests are: (1) oral salt loading; (2) saline infusion; (3) captopril challenge and (4) fludrocortisone suppression test. Confirmation of PA can avoid that patients with a false positive ARR would inappropriately undergo costly and harmful lateralization procedures. If confirmatory testing is positive, further investigations are directed toward determining the subtype of PA, as the treatment differs for each subtype.