Plasma aldosterone response to ACTH stimulation test for diagnosis of primary aldosteronism: a cross-sectional study

TL;DR

This study shows that measuring plasma aldosterone 20 minutes after an ACTH test can help diagnose primary aldosteronism without needing more complex tests.

Contribution

The study introduces a simplified diagnostic method for primary aldosteronism using a single ACTH stimulation test.

Findings

PAC at 20 minutes after ACTH stimulation was significantly associated with PA diagnosis.

The proposed cut-off of 52 ng/dL achieved 71.4% sensitivity and 96.6% specificity for PA diagnosis.

The method may be useful when standard confirmation tests for PA are not feasible.

Abstract

The diagnosis of primary aldosteronism (PA) requires screening and confirmation testing. The present study examined whether the 1 µg ACTH stimulation test for plasma aldosterone concentration (PAC) can accurately diagnose PA by bypassing the regular confirmatory steps of PA diagnosis.

A cross-sectional study with a total of 36 patients with an aldosterone-renin ratio (ARR) > 20 ng/dL per ng/m/hr were included. The confirmation test for PA was performed by saline infusion and the patients were categorized into PA and non-PA. PAC was collected at 20 and 40 min after 1 µg ACTH stimulation test. Multivariable logistic regression analysis was performed, and the associations are presented as odds ratios (OR) and 95% confidence intervals (CI). Diagnostic accuracy is presented as AuROC.

Multivariable analysis found only PAC at 20 min after ACTH stimulation showed significant association with a diagnosis of PA (OR 1.18, 95%CI (0.99, 1.31), p = 0.040). AuROC for this value was 0.95 and the proposed cut-off was 52 ng/dL with a sensitivity of 71.4% and a specificity of 96.6%.

Diagnosing PA may be aided by PAC at 20 min following 1 µg ACTH stimulation. This value may be used with patients for whom the confirmation test for PA cannot be conducted.

The online version contains supplementary material available at 10.1186/s12902-024-01563-y.

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