Objective: To explore the value of the midnight 1 mg dexamethasone suppression test combined with adrenocorticotropic hormone (ACTH) stimulation test in the diagnosis of primary aldosteronism (PA) subtypes. Methods: A cross-sectional study. Clinical data of patients diagnosed with PA at the First Medical Center of Chinese PLA General Hospital from January 2020 to September 2022, who completed the midnight 1 mg dexamethasone suppression test combined with ACTH stimulation test, were analysed retrospectively. The clinical characteristics and trial results of patients with aldosterone-producing adenoma (APA) and idiopathic hyper aldosteronism (IHA)were compared. The efficacy of the midnight 1 mg dexamethasone suppression test combined with ACTH stimulation test in distinguishing APA and IHA was evaluated by drawing receiver operating characteristic (ROC) curves, and the cut-off value of the diagnostic indicator was determined with the maximum Youden index. Results: A total of 82 patients with PA were included, including 43 males and 39 females, aged (50.8±11.4) years old. They were divided into APA group (n=49) and IHA group (n=33) based on PA subtype. There was no statistically significant difference in body mass index, systolic and diastolic blood pressure between the two groups (all P>0.05). The blood potassium and orthostatic renin levels in the APA group were lower than those in the IHA group, and the differences were statistically significant (all P<0.001). The orthostatic plasma aldosterone concentration (PAC), orthostatic aldosterone to renin ratio (ARR), PAC before and after captopril challenge test(CCT), ARR after CCT, PAC before and after saline infusion test (SIT), and the proportion of unilateral lesions in the APA group were all higher than those in the IHA group, and the differences were statistically significant (all P<0.001). After the midnight 1 mg dexamethasone suppression test combined with ACTH stimulation test (30, 60, 90, 120 min), the PAC and PAC/cortisol levels in the APA group were significantly higher than those in the IHA group (all P<0.05). The PAC at 90 min showed the highest diagnostic capability according to the area under the ROC(AUC) (0.930,95%CI:0.874-0.986), and the Youden index was the highest at a PAC cut-off value of 39.05 ng/dl(0.766). The sensitivity and specificity for distinguishing APA from IHA were 91.8% and 84.8%, respectively. Conclusions: The midnight 1 mg dexamethasone suppression test with ACTH stimulation test could be useful for differentiating the subtypes of PA. Among them, the PAC and PAC/cortisol at 90 min showed best diagnostic efficacy.
目的： 探讨午夜1 mg地塞米松抑制试验联合促肾上腺皮质激素（ACTH）兴奋试验在原发性醛固酮增多症（PA）分型诊断中的价值。 方法： 横断面研究。回顾性分析2020年1月至2022年9月解放军总医院第一医学中心确诊为PA并完成午夜1 mg地塞米松抑制试验联合ACTH兴奋试验患者的临床资料，分析比较醛固酮瘤（APA）和特发性醛固酮增多症（IHA）患者的临床特征及试验结果。通过绘制受试者工作特征（ROC）曲线评估午夜1 mg地塞米松抑制试验联合ACTH兴奋试验对鉴别APA和IHA的效能，以约登指数最大确定诊断指标的cut-off值。 结果： 共纳入82例PA患者，男43例，女39例，年龄（50.8±11.4）岁。根据PA类型分为APA组（n=49）和IHA组（n=33）。两组的体质指数、收缩压及舒张压差异均无统计学意义（均P>0.05）。APA组血钾、立位肾素均低于IHA组，差异均有统计学意义（均P<0.001）；APA组立位血浆醛固酮浓度（PAC）、立位醛固酮与肾素比值（ARR）、卡托普利试验（CCT）前和后PAC、CCT后ARR、盐水输注试验（SIT）前和后PAC、单侧病变比例均大于IHA组，差异均有统计学意义（均P<0.001）。午夜1 mg地塞米松抑制试验联合ACTH兴奋试验后30、60、90、120 min APA组PAC及PAC/皮质醇均高于IHA组，差异均有统计学意义（均P<0.05）。试验后90 min PAC的ROC曲线下面积（AUC）最大，0.930（95%CI：0.874~0.986），PAC的cut-off值为39.05 ng/dl时约登指数最大（0.766），鉴别APA与IHA的灵敏度和特异度分别为91.8%和84.8%。 结论： 午夜1 mg地塞米松抑制试验联合ACTH兴奋试验在PA分型中具有一定临床价值，能够较好鉴别APA和IHA，其中90 min PAC及PAC/皮质醇的诊断效能最佳。.