title: Confirmatory testing in primary aldosteronism: extensive medication switching is not needed in all patients.
abstract: OBJECTIVE
  Confirmatory testing of suspected primary aldosteronism (PA) requires an extensive medication switch that can be difficult for patients with severe complicated hypertension and/or refractory hypokalemia. For this reason, we investigated the effect of chronic antihypertensive medication on confirmatory testing results. To allow the results to be interpreted, the reproducibility of confirmatory testing was also evaluated.
  
  
  METHODS
  The study enrolled 114 individuals with suspected PA who underwent two confirmatory tests. The patients were divided into two groups. In Group A, both tests were performed on the guidelines-recommended therapy, i.e. not interfering with the renin-angiotensin-aldosterone system. In Group B, the first test was performed on chronic therapy with the exclusion of thiazides, loop diuretics, and aldosterone antagonists; and the second test was performed on guidelines-recommended therapy. Saline infusion, preceded by oral sodium loading, was used to suppress aldosterone secretion.
  
  
  RESULTS
  Agreement in the interpretation of the two confirmatory tests was observed in 84 and 66% of patients in Groups A and B respectively. For all 20 individuals in Group A who ever had end-test serum aldosterone levels ≥240 pmol/l, aldosterone was concordantly nonsuppressible during the other test. Similarly, for all 16 individuals in Group B who had end-test serum aldosterone levels ≥240 pmol/l on modified chronic therapy, aldosterone remained nonsuppressible with guidelines-recommended therapy.
  
  
  CONCLUSIONS
  Confirmatory testing performed while the patient is on chronic therapy without diuretics and aldosterone antagonists can confirm the diagnosis of PA, provided serum aldosterone remains markedly elevated at the end of saline infusion.
authors.affiliation: Departments of Internal Medicine Nuclear Medicine, Charles University Prague, University Hospital Hradec Kralove, Sokolska 581, Hradec Kralove, Czech Republic.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Solar
authors.forename: Eva
authors.initials: E
authors.lastname: Malirova
authors.forename: Marek
authors.initials: M
authors.lastname: Ballon
authors.forename: Radek
authors.initials: R
authors.lastname: Pelouch
authors.forename: Jiri
authors.initials: J
authors.lastname: Ceral
mesh_terms: D000328:Adult; D000368:Aged; D000450:Aldosterone / Q000097:blood; D000465:Algorithms; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000627:therapeutic use; D003940:Diagnostic Techniques, Endocrine; D004232:Diuretics / Q000008:administration & dosage / Q000627:therapeutic use; D057915:Drug Substitution / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D006929:Hyperaldosteronism / Q000175:diagnosis* / Q000188:drug therapy* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D000451:Mineralocorticoid Receptor Antagonists / Q000008:administration & dosage / Q000627:therapeutic use*; D020380:Needs Assessment / Q000706:statistics & numerical data; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000502:physiology; D054928:Validation Studies as Topic; D055815:Young Adult
chemical_list: D000959:Antihypertensive Agents; D004232:Diuretics; D000451:Mineralocorticoid Receptor Antagonists; D000450:Aldosterone