Evaluating simplified confirmation strategies for primary aldosteronism diagnosis

The diagnostic process for primary aldosteronism (PA) is cumbersome, encompassing screening, suppression testing, and subtype differentiation. Current guidelines indicate that patients with hypokalemia may bypass suppression testing if plasma aldosterone concentration (PAC) > 20 ng/dL and renin is suppressed (plasma renin activity (PRA) below the detection limit or direct renin concentration (DRC) ≤ 8.2 mU/L). The 2025 Endocrine Society guideline further suggests that suppression testing can be omitted for patients without surgical intention, allowing direct initiation of mineralocorticoid receptor antagonist therapy. Nevertheless, these criteria remain restrictive or poorly defined. Consequently, a more universally applicable simplified diagnostic strategy is needed, particularly because hypokalemia occurs in fewer than 40% of PA cases. This study was a cross-sectional study. A total of 1,235 patients with hypertension, who visited the Hypertension Department of Xinjiang Uygur Autonomous Region People’s Hospital from December 2020 to December 2023 and were diagnosed with PA by saline infusion test (SIT), were enrolled. This study evaluated two indicators: PAC and the presence of spontaneous hypokalemia, in terms of their diagnostic efficacy for PA. Patients with positive screening test and seated PAC of > 30 ng/dL showed the highest specificity at 100% (95% CI 99.17–100.00%) and positive predictive value (PPV) at 100% (95% CI 94.87–100.00%), The minimum acceptable were PAC of > 20 ng/dL showed specificity at 96.61% (95% CI 94.46–98.09%) and Sensitivity at 31.27% (95% CI 28.06–34.63%); In Among patients with normokalemia, PAC > 30 ng/dL showed the highest specificity at 100% (95% CI 98.99–100.00%) and PPV at 100% (95% CI 85.75–100.00%), The minimum acceptable were PAC of > 20 ng/dL showed specificity at 95.88% (95% CI 93.29–97.68%); Among patients with hypokalemia, PAC > 20 ng/dL showed the highest specificity at 100% (95% CI 95.38–100.00%) and PPV at 100% (95% CI 97.22–100.00%). Our study shows among patients with positive results from the screening, suppression testing for PA can bypass if seated PAC > 20 ng/dL.