Clinical value of captopril test in noninvasive diagnosis of aldosterone-producing adenoma / 北京大学学报(医学版)

ABSTRACT

OBJECTIVE@#To analyze the clinical characteristics of aldosterone-producing adenoma (APA) subtypes in primary aldosteronism (PA) and the application value of captopril challenge test (CCT) in adenomas. And to find out the clinically specific non-invasive index for identifying APA subtypes from PA.@*METHODS@#The clinical data of hospitalized patients with hypertension were retrospectively collected. All the patients were conducted with the CCT and 90 patients with PA were confirmed. Among them, 34 patients were confirmed to have APA by surgery. The clinical indicators of the two groups of patients including plasma aldosterone concentration (PAC), aldosterone inhibition rate (%), and aldosterone to renin ratio (ARR) before and after the CCT were compared, the receiver operating characteristic (ROC) curves for the relevant indicators before and after the CCT drawn, and the areas under the curve (AUC) compared. The ROC curves were used to analyze the efficiency of the different CCT diagnostic criteria for diagnosing APA.@*RESULTS@#Compared with the PA group, the duration of hypertension was shorter, the incidence of hypokalemia was higher, and the average serum potassium level was lower when APA was diagnosed. There were no significant differences in blood pressure level, gender, serum sodium and body mass index between the two groups. Compared with PA population, APA group had higher PAC and ARR whether before or after the CCT, but lower plasma renin concentration (PRC). In APA patients, the mean degree of PAC declined after CCT was approximately 5.7%, but 5% with that of PA. As for diagnosing, ARR before or after CCT had diagnostic value for APA, in which the ARR cut-off point was 7.12, which yielded a sensitivity and specificity of 35.85% and 77.78%. The cut-off point of ARR after CCT was 4.23, with a sensitivity of 71.43% and specificity of 62.22%. For the diagnosis, the ARR before and after CCT were of no significant difference. However, the diagnostic specificity of ARR>7.12 combined with hypokalemia was up to 80%.@*CONCLUSION@#ARR before or after CCT have clinical value for the diagnosis of APA from PA, when combined with hypokalemia yielded high specificity.