title: Unadjusted Plasma Renin Activity as a "First-Look" Test to Decide Upon Further Investigations for Primary Aldosteronism.
abstract: The authors sought to define the 95th percentile of plasma renin activity (PRA) in a sample of patients with confirmed primary aldosteronism (PA) prior to adjustment of medications as a practical "first-look" test to identify those with very low ultimate likelihood of having PA. The aldosterone to renin ratio (ARR) was measured without adjustment of antihypertensive medications, with further workup as appropriate. Two groups were defined: patients with surgically "confirmed PA" (n=58) and patients with "high-probability PA" (n=59), defined as having any of the following: computed tomography-confirmed adrenal adenoma plus lateralizing adrenal vein sampling (AVS) without surgery, high ARR and hypokalemia but nonlateralizing AVS, or ARR more than four times the upper limit of normal. The PRA 95th percentile was 1.0 ng/mL/h. All outliers had hypokalemia and two had adrenal adenomas. There was no difference between the confirmed and high probability groups. In the absence of highly suspicious clinical features, patients with unadjusted PRA >1.0 ng/mL/h do not warrant further investigation for PA.
authors.affiliation: Department of Medicine, University of Calgary, Calgary, AB.
authors.forename: Peter
authors.initials: P
authors.lastname: Rye
authors.affiliation: Calgary Laboratory Services, Department of Pathology and Laboratory Medicine, Section of Clinical Biochemistry, University of Calgary, Calgary, AB.
authors.forename: Alex
authors.initials: A
authors.lastname: Chin
authors.affiliation: Department of Surgery, University of Calgary, Calgary, AB.
authors.forename: Janice
authors.initials: J
authors.lastname: Pasieka
authors.affiliation: Department of Radiology, University of Calgary, Calgary, AB.
authors.forename: Benny
authors.initials: B
authors.lastname: So
authors.affiliation: Department of Surgery, University of Calgary, Calgary, AB.
authors.forename: Adrian
authors.initials: A
authors.lastname: Harvey
authors.affiliation: Interim Division Head of Endocrinology, University of Calgary, Calgary, AB.
authors.forename: Gregory
authors.initials: G
authors.lastname: Kline
mesh_terms: D000328:Adult; D000450:Aldosterone / Q000097:blood*; D000959:Antihypertensive Agents / Q000627:therapeutic use; D015992:Body Mass Index; D005260:Female; D006801:Humans; D006929:Hyperaldosteronism / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy / Q000601:surgery; D006973:Hypertension / Q000097:blood / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D000451:Mineralocorticoid Receptor Antagonists / Q000627:therapeutic use; D012083:Renin / Q000097:blood*; D012189:Retrospective Studies; D013148:Spironolactone / Q000627:therapeutic use; D014057:Tomography, X-Ray Computed
chemical_list: D000959:Antihypertensive Agents; D000451:Mineralocorticoid Receptor Antagonists; D013148:Spironolactone; D000450:Aldosterone; D012083:Renin