Abstract
This study aimed to evaluate the diagnostic accuracy of 24-hour urinary aldosterone (UALD) for primary aldosteronism (PA) in Northeast China. A total of 423 patients with hypertension were consecutively enrolled. After 1:2 propensity score matching (PSM), 100 patients were classified into the PA group, and 194 patients were classified into the essential hypertension (EH) group. The clinical characteristics and biochemistry measurements were collected and analyzed. A receiver operating characteristic (ROC) curve was generated, and the area under the curve (AUC) was calculated to determine optimal diagnostic thresholds. No significant difference in age was observed between the groups (PA: 53.4 ± 11.3 years vs. EH: 52.8 ± 11.3 years, p > 0.05). The median 24-hour UALD was significantly greater in the PA group (6.4 [3.7, 13.9] µg/24 h vs. 4.8 [2.5, 7.8] µg/24 h, p < 0.05), with levels declining with age in both cohorts. The optimal UALD cutoff value was 11.4 µg/24 h (AUC = 0.652; Youden index = 0.257). For patients over 55 years, the 24-hour urinary aldosterone-to-creatinine ratio (UACR) showed superior diagnostic performance, with an optimal cutoff of 0.8 µg/mmol/L (AUC = 0.695). 24-Hour UALD was a promising diagnostic marker for PA in North China, whereas 24-hour UACR might increase accuracy in older populations. However, further studies are needed to validate these findings.