Plasma Aldosterone: Comparison of a New Automated Assay with a Standard Extraction Method

A variety of clinical conditions present with an abnormality in aldosterone concentration. Primary hyperaldosteronism (PHA), long considered a rare cause of hypertension (<2% of the hypertensive population), has in the past decade been suggested to be present in 3%–32% of hypertensive patients (1). Although commercially available reagent sets have made it technically easier to measure plasma aldosterone concentration (PAC) for PHA analysis, these methods are often time-consuming and limited to small throughput, with reported problems arising with their application to assay PAC from patients with chronic renal failure (CRF) (2)(3)(4).We previously validated a new automated method for measuring direct renin (5), and because there was little, if any, information on the evaluation of a similar method for aldosterone, we applied this automated method to measure PAC and compared the results with those obtained from a standard extraction method. We compared measurements of samples from hypertensive and normotensive individuals with CRF and applied samples from hypertensive or normotensive individuals without CRF as controls. We also evaluated whether different anticoagulants have any effect on PAC measured by this automated method.The study participants …