Seated Saline Suppression Test Is Comparable With Captopril Challenge Test for the Diagnosis of Primary Aldosteronism: A Prospective Study

Bin Liu, Jinbo Hu, Ying Song, Wenwen He, Qingfeng Cheng, Zhihong Wang, Zhengping Feng, Zhipeng Du, Zhixin Xu, Jun Yang, Qifu Li, Shumin Yang, the Chongqing Primary Aldosteronism Study (CONPASS) Group

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13 Citations (Scopus)

Abstract

OBJECTIVE: The saline suppression test (SST) and captopril challenge test (CCT) are commonly used confirmatory tests for primary aldosteronism (PA). Seated SST (SSST) has been reported to be superior to recumbent SST. Whether SSST is better than CCT remains unclear. We aimed to compare the diagnostic accuracy of SSST and CCT in a prospective study. METHODS: Hypertensive patients at a high risk of PA were consecutively included. Patients with an aldosterone-renin ratio of ≥1.0 ng/dL/μIU/mL were asked to complete SSST, CCT, and the fludrocortisone suppression test (FST). Using FST as a reference standard (plasma aldosterone concentration [PAC] post FST ≥ 6.0 ng/dL), area under the receiver-operating characteristic curve (AUC), sensitivity, and specificity of SSST and CCT were calculated, and multiple regression analyses were performed to identify potential factors leading to false diagnosis. RESULTS: A total of 196 patients diagnosed with PA and 73 with essential hypertension completed the study. Using PAC post SSST and PAC post CCT to confirm PA, SSST and CCT had comparable AUCs (AUCSSST 0.87 [95% CI 0.82-0.91] vs AUCCCT 0.88 [0.83-0.95], P = .646). When PAC post SSST and post CCT were set at 8.5 and 11 ng/dL, respectively, the sensitivity and specificity of SSST (0.72 [0.65, 0.78] and 0.86 [0.76, 0.93]) and CCT (0.73 [0.67, 0.80] and 0.85 [0.75, 0.92]) were not significantly different. In the multiple regression analyses, 1-SD increment of sodium intake resulted in a 40% lower risk of false diagnosis with SSST. CONCLUSION: SSST and CCT have comparable diagnostic accuracy. Insufficient sodium intake decreases the diagnostic efficiency of SSST but not of CCT. Since CCT is simpler and cheaper, it is preferred over SSST.

Original languageEnglish
Pages (from-to)326-333
Number of pages8
JournalEndocrine Practice
Volume27
Issue number4
DOIs
Publication statusPublished - Apr 2021

Keywords

  • captopril challenge test
  • comparison
  • diagnostic accuracy
  • primary aldosteronism
  • seated saline suppression test

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