Jahan Sharmin, Lu Zhong X, Akram Muhammad, Hasanat M A, Fariduddin M, Fuller Peter J, Yang Jun
Centre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Vic, Australia; Department of Endocrinology and Metabolism, BSMMU, Dhaka, Bangladesh; Department of Molecular and Translational Science, Monash University, Vic, Australia.
Department of Medicine, Monash University, Clayton, Vic, Australia; Monash Health Pathology, Monash Health, Clayton, Vic, Australia.
Pathology. 2025 Jun 6. doi: 10.1016/j.pathol.2025.04.003.
Primary aldosteronism (PA) is the most common cause of endocrine hypertension. Current screening uses the plasma aldosterone-to-renin ratio (ARR) followed by confirmatory testing with one of several tests. The saline suppression test (SST) is widely used but contraindicated in patients with renal insufficiency or congestive heart failure. The captopril challenge test (CCT) offers a safe, inexpensive and convenient alternative to the SST, but diagnostic thresholds and reported accuracy vary between centres. Furthermore, none of the previous comparative studies have been carried out in low- and middle-income countries, where the affordability of the CCT may offer distinct advantages. This study aimed to evaluate the diagnostic accuracy of the CCT compared to the SST in a Bangladeshi population. In this prospective study, consecutive hypertensive patients with an ARR >50 pmol/mIU underwent both the SST and CCT. Using the SST as the reference standard, where plasma aldosterone concentration (PAC) post SST ≥170 pmol/L is considered diagnostic of PA, the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and negative and positive predictive values of different diagnostic criteria for the CCT were calculated. A total of 103 patients completed both confirmatory tests. The diagnostic accuracy of the post-captopril PAC at both 1 h and 2 h outperformed post-captopril ARR or the percentage suppression of PAC (AUC 0.77, 0.70 and 0.56, respectively; p<0.001). PACs >333 pmol/L at 1 h and 2 h post administration of captopril demonstrated sensitivities of 54.5% and 44.4%, with specificities of 91.5% and 93.6%, respectively. A post-captopril PAC <151 pmol/L effectively ruled out PA with 96.4% sensitivity, while a PAC >380 pmol/L ruled in the diagnosis of PA with 95.7% specificity. Overall, our findings indicate that the CCT, based on post-captopril PAC, achieves comparable diagnostic accuracy to the seated SST. The diagnostic performance was similar at either 1 h or 2 h post administration of captopril, suggesting that 1 h may be preferred in a CCT protocol for efficiency. The CCT represents a safe and convenient confirmatory test to guide decisions on PA subtyping or medical treatment, especially in resource-limited settings.
原发性醛固酮增多症（PA）是内分泌性高血压最常见的病因。目前的筛查采用血浆醛固酮与肾素比值（ARR），随后通过几种检测方法之一进行确诊试验。生理盐水抑制试验（SST）被广泛应用，但肾功能不全或充血性心力衰竭患者禁用。卡托普利激发试验（CCT）为SST提供了一种安全、廉价且便捷的替代方法，但不同中心的诊断阈值和报道的准确性有所不同。此外，以往的比较研究均未在低收入和中等收入国家开展，而在这些国家，CCT的可承受性可能具有明显优势。本研究旨在评估在孟加拉人群中，CCT与SST相比的诊断准确性。在这项前瞻性研究中，连续入选ARR>50 pmol/mIU的高血压患者接受SST和CCT。以SST作为参考标准，即SST后血浆醛固酮浓度（PAC）≥170 pmol/L被视为PA的诊断标准，计算CCT不同诊断标准的受试者操作特征曲线下面积（AUC）、敏感性、特异性以及阴性和阳性预测值。共有103例患者完成了两项确诊试验。卡托普利给药后1小时和2小时的PAC诊断准确性均优于卡托普利给药后的ARR或PAC抑制百分比（AUC分别为0.77、0.70和0.56；p<0.001）。卡托普利给药后1小时和2小时PAC>333 pmol/L的敏感性分别为54.5%和44.4%，特异性分别为91.5%和93.6%。卡托普利给药后PAC<151 pmol/L以96.4%的敏感性有效排除PA，而PAC>380 pmol/L以95.7%的特异性确诊PA。总体而言，我们的研究结果表明，基于卡托普利给药后PAC的CCT与坐位SST具有相当的诊断准确性。卡托普利给药后1小时或2小时的诊断性能相似，提示在CCT方案中，为提高效率，1小时可能更可取。CCT是一种安全便捷的确诊试验，可指导PA亚型分类或药物治疗决策，尤其是在资源有限的环境中。
