Is random screening of value in detecting glucocorticoid-remediable aldosteronism within a hypertensive population?

Glucocorticoid-remediable aldosteronism (GRA) is a rare inherited cause for hypertension associated with a significant morbidity and mortality at an early age. Individuals with this abnormality frequently present with severe hypertension which is resistant to standard antihypertensive therapy, a strong family history of hypertension, intracranial haemorrhage, and sporadic hypokalaemia. However many affected individuals may appear phenotypically indistinguishable from normal essential hypertensives but remain at high risk of morbidity and mortality. To determine how effective random or targeted screening of hypertensive patients is for the detection of GRA. A prospective study involving the screening of 300 hypertensive patients chosen at random attending the Aberdeen Hypertension Clinic and, during the same period, the targeted screening of patients with a medical and family history suggestive of GRA. A University hospital with a primary catchment of 500,000 inhabitants and a hypertension clinic population of over 8500 patients. Random screening failed to identify any GRA mutation-positive individuals. Targeted screening of selected individuals revealed two index families and four further families containing 40 mutation-positive individuals. Targeted screening of hypertensive individuals with a family history of hypertension, cerebral haemorrhage, a history of hypertension from an early age, resistant hypertension which has proven difficult to control and hypokalaemia revealed two index cases and four further individuals and 30 hypertensive and 10 normotensive members of their families with GRA.