Diagnostic value of 24-h urinary aldosterone and related biomarkers for screening primary aldosteronism in medication-exposed populations

Objective: To evaluate the screening value of 24-hour urinary aldosterone (24h-Uald) and the urinary aldosterone-to-renin ratio (UARR) for primary aldosteronism (PA in hypertensive patients under conditions of ongoing antihypertensive medication use. Methods: Hypertensive patients who underwent PA screening at our hospital between August 2024 and August 2025 were retrospectively enrolled. Baseline clinical characteristics and biochemical parameters were collected while patients were receiving ongoing antihypertensive therapy. Multivariable logistic regression analysis was performed to assess the independent associations of 24h-Uald and UARR with PA. Diagnostic performance was evaluated using receiver operating characteristic (ROC) curve analysis. Results: Both 24h-Uald and UARR levels were significantly higher in patients with PA than in those with essential hypertension (EH) (P < 0.05). After adjustment for potential confounders, including age, body mass index, renal function, and history of coronary artery disease, 24h-Uald and UARR remained independently associated with PA. ROC curve analysis demonstrated a modest diagnostic performance for 24h-Uald (AUC = 0.657), whereas UARR exhibited excellent diagnostic accuracy (AUC = 0.862). Conclusions: Under conditions of ongoing antihypertensive medication use, the diagnostic performance of 24h-Uald alone for PA screening is limited. In contrast, UARR, incorporating renin measurements, demonstrates higher diagnostic accuracy and greater clinical utility.