The present study was undertaken prospectively to compare the diagnostic significance of the seated saline suppression testing (SSST) with the captopril challenge testing (CCT) in hypertensive patients with suspected primary aldosteronism (PA) using the fludrocortisone suppression testing (FST) as the reference standard, and to investigate the optimal cutoff of SSST for differentiating PA from other forms of hypertension.
The diagnosis of primary aldosteronism (PA) typically requires at least one confirmatory test. Four tests are commonly recommended by the Endocrine Society guideline, namely, oral sodium loading, saline infusion, fludrocortisone administration with oral sodium loading, and captopril challenge testing (CCT). Of these, fludrocortisone suppression testing (FST) has been considered the most reliable, but is cumbersome, difficult to perform, and relatively expensive, requiring hospital admission for several days. Alternative approaches to FST have included saline suppression testing (SST), Which requiring patients staying in the recumbent position for at least 1 h before and during the infusion of 2 L of 0.9% saline IV over 4 h. This approach also has the disadvantages of brings much inconvenience to the patient (such as urination or defecation, etc.). Ashraf H. et al. have reported that seated SST (SSST) is more sensitive than recumbent SST (RSST), especially for posture-responsive PA (95.8% versus 33.3%), however, in this small scale study, only 31 patients was PA and only three patients was tested negative for PA by FST. Specificity of each form of SST was unable to estimate and meaningful receiver operating characteristic (ROC) curve analyses could not be performed. Furthermore, it is lack of study in Chinese people. In addition, the investigators have previously found the CCT was as accurate as the FST and plasma aldosterone concentration (PAC) post-CCT is the best approach to interpret the results of the CCT. The present study was undertaken prospectively to compare the diagnostic significance of the SSST with the CCT in hypertensive patients with suspected PA using the FST as the reference standard, and to investigate the optimal cutoff of SSST for differentiating PA from other forms of hypertension.
Study Type
OBSERVATIONAL
Enrollment
200
Seated saline infusion test: All participants received the infusion of 2 liters of 0.9% saline over 4 h in seated posture. Fludrocortisone suppression test:Patients received 0.1 mg oral fludrocortisone every 6 h for 4 days, together with slow-release potassium chloride and sodium chloride supplements. Captopril challenge test:Patients received 50 mg captopril orally at 8-9 a.m. after sitting or standing for at least 1 h. Blood samples were drawn at time zero and 2 h after the challenge.
The First Affilated Hospital of Chongqing Medical University
Chongqing, Chongqing Municipality, China
Diagnostic Accuracy of Seated Saline Suppression Test
compare the diagnostic significance of the SSST with the CCT in hypertensive patients with suspected PA using the FST as the reference standard
Time frame: 2 weeks
The cutoff of SSST for diagnosis of PA
investigate the optimal cutoff of SSST for differentiating PA from other forms of hypertension.
Time frame: 2 weeks
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