Intraindividual variability of serum aldosterone and its implication for primary aldosteronism screening.
J Clin Endocrinol Metab 2022;
108:1143-1153. [PMID:
36413507 DOI:
10.1210/clinem/dgac679]
[Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 11/10/2022] [Accepted: 11/18/2022] [Indexed: 11/23/2022]
Abstract
CONTEXT
Primary aldosteronism (PA) screening relies on an elevated aldosterone to renin ratio with a minimum aldosterone level, which varies from 10 to 15 ng/dL (277 to 415.5 pmol/L) using immunoassay.
AIM
To evaluate intraindividual coefficient of variation (CV) of aldosterone and aldosterone to direct renin concentration ratio (A/DRC) and its impact on PA screening.
METHODS
A total of 671 aldosterone and DRC measurements were performed by the same chemiluminescence assays in a large cohort of 216 patients with confirmed PA and at least two screenings.
RESULTS
The median intraindividual CV of aldosterone and A/DRC was 26.8% and 26.7%. Almost 40% of the patients had at least one aldosterone level <15 ng/dL, 19.9% had at least two aldosterone levels <15 ng/dL and 16.2% had mean aldosterone levels <15 ng/dL. A lower cut-off of 10 ng/dL was associated with false negative rates for PA screening of 14.3% for a single aldosterone measurement, 4.6% for two aldosterone measurements and only 2.3% for mean aldosterone levels. Considering the minimum aldosterone, true positive rate of aldosterone thresholds was 85.7% for 10 ng/dL and 61.6% for 15 ng/dL. An A/DRC >2 ng/dL/µIU/mL had a true positive rate for PA diagnosis of 94.4% and 98.4% when based on one or two assessments, respectively. CV of aldosterone and A/DRC were not affected by sex, use of interfering anti-hypertensive medications, PA lateralization, hypokalemia, age and number of hormone measurements.
CONCLUSION
Aldosterone concentrations had a high CV in PA patients, which results in an elevated rate of false negative test in a single screening for PA. Therefore, PA screening should be based in at least two screenings with concomitant aldosterone and renin measurements.
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