Exploration Of The Seated Saline Suppression Test For The Diagnosis Of Primary Aldosteronism In The Chinese Population

Abstract

We prospectively investigated the accuracy of the seated saline suppression test (SSST) in 113 patients with hypertension (including 93 primary aldosteronism [PA] and 20 essential hypertension patients) in the Department of Endocrinology and Metabolism. Each patient underwent a recumbent saline suppression test (RSST) and SSST. The accuracy of the SSST for a confirmative PA diagnosis and subtype classification was evaluated and compared with the RSST. The area under the receiver operating characteristic (ROC) curve of plasma aldosterone concentration (PAC) for the SSST was significantly greater than that for the RSST (0.945±0.0199 vs. 0.828 ± 0.0404; P<.05). The ROC analysis showed that the optimal PAC cut-off values were 12.94 ng/dL for the SSST (sensitivity 86.02%, specificity 95%; Youden index [YI] 0.810) and 12.04 ng/dL for the RSST (sensitivity 83.15%, specificity 57%; YI 0.401). The optimal PAC cut-off value for classifying aldosterone-producing adenoma and idiopathic hyperaldosteronism was 18.12 ng/dL for the SSST (sensitivity 73.5%, specificity 79.5%). No patients experienced adverse events during the SSST. The SSST is safe and convenient for PA diagnosis. The accuracy of the SSST for a confirmatory diagnosis of PA was better than that of the RSST. The SSST is a reliable alternative for PA confirmation in Chinese individuals. APA = aldosterone-producing adenoma; ARR = aldosterone to renin ratio; AVS = adrenal vein sampling; CT = computed tomography; EH = essential hypertension; IHA = idiopathic hyperaldosteronism; MRI = magnetic resonance imaging; PA = primary aldosteronism; PAC = plasma aldosterone concentration; PRA = plasma renin activity; ROC = receiver operating characteristic; RSST = recumbent saline suppression test; SSST = seated saline suppression test; YI = Youden index.