Primary hyperaldosteronism (PA) is the most frequent cause of secondary hypertension. PA detection is of particular importance, because it provides opportunity for targeted treatment (surgical for APA and medical for BAH), and because it has been demonstrated that PA patients are more prone to cardiovascular events and target organ damage than essential hypertensives. The Endocrine Society Guidelines stated the categories of hypertensive patients with relatively high prevalence of PA, that should undergo a screening test: -resistant hypertension; -hypertension grade 2 or 3; -hypertension with spontaneous or diuretic-induced hypokalaemia; -hypertension with adrenal incidentaloma; -hypertension and a family history of early-onset hypertension or cerebrovascular accident at a young age; -all hypertensive first-degree relatives of PA patients PA. However, recent studies indicate that other categories of patients may be at increased risk of PA, including hypertensive patients with metabolic syndrome (MS), type 2 diabetes mellitus (T2DM) and obstructive sleep apnoea (OSA). Aldosterone/renin ratio (ARR) is considered the best screening test. Several confounding factor, in particular interfering drugs, should be considered during the screening. Moreover, it should be noted that the test may perform differently if renin instead of plasma renin activity is measured together with aldosterone. It remains to be determined the potential benefit of screening all hypertensives for PA. Widespread screening would result in a large increase in costs for screening and confirmation of PA, but on the other hand, would offer to all PA patients the opportunity of a cure or targeted pharmacotherapy. In light of the high prevalence of low renin hypertension, it is important to emphasize that an increased ARR is not itself diagnostic of PA and a confirmatory test is always required to avoid a high number of hypertensive patients inappropriately undergoing costly and potentially harmful lateralisation procedures. Although Endocrine Society Guidelines clearly recommend performing a confirmatory test, the choice of confirmatory test remains a matter of debate and there is currently insufficient direct evidence to recommend one over the others. In our Unit we perform the intravenous saline load and we suggest to perform a confirmatory test that includes NaCl administration and to use captopril test only for those patients at risk for volume expansion.
30 Apr - 04 May 2011
European Society of Endocrinology