Edinburgh Centre for Endocrinology and Diabetes, Royal Infirmary of Edinburgh, Edinburgh, UK.
Research and Clinical Innovation, Royal Centre for Defence Medicine, Birmingham, UK.
Clin Endocrinol (Oxf). 2019 Nov;91(5):608-615. doi: 10.1111/cen.14071. Epub 2019 Aug 14.
The diagnostic value of a single measurement of serum cortisol as a first step in the investigation of suspected adrenal insufficiency remains unclear. Previously proposed criteria have not been validated, and little is known regarding the performance of the test outwith morning samples in outpatients. We aimed to identify and validate criteria for morning and afternoon serum cortisol which could be used to determine which individuals require dynamic testing, in both outpatient and medical inpatient settings.
We performed a retrospective analysis of 2768 patients attending endocrinology clinics and patients admitted to general medical units in two hospitals in Edinburgh, UK. In baseline samples from the short synacthen test, thresholds which identified a subnormal-stimulated serum cortisol (<430 nmol/L using the Abbott Architect assay) with 95% sensitivity were identified. Criteria drawn from data in patients attending outpatient clinics in one hospital were tested in additional outpatient and inpatient validation cohorts.
A morning (8 am-12 pm) serum cortisol of <275 nmol/L identified subnormal-stimulated cortisol with 96.2% sensitivity. For afternoon (12 pm-6 pm) samples, a cut-off of <250 nmol/L achieved 96.1% sensitivity. Sensitivity was maintained when the criteria were applied to outpatients in the validation cohort for both morning and afternoon samples. For inpatients, the test was sufficiently sensitive in morning samples only.
A single measurement of serum cortisol carries the potential to significantly reduce the need for dynamic testing in the investigation of adrenal insufficiency, whether this is taken in morning or afternoon outpatient clinics, or in morning samples from medical inpatients.
作为疑似肾上腺功能不全患者检查的第一步，单次血清皮质醇测量的诊断价值尚不清楚。以前提出的标准尚未得到验证，并且对于在门诊患者中外周血样本之外进行测试的测试性能知之甚少。我们旨在确定和验证清晨和下午血清皮质醇的标准，这些标准可用于确定哪些个体需要进行动态测试，无论是在门诊还是住院患者中。
我们对 2768 名在英国爱丁堡两家医院的内分泌科诊所就诊的患者和住院患者进行了回顾性分析。在短 Synacthen 测试的基础样本中，确定了以 95%敏感性识别出低刺激血清皮质醇（使用 Abbott Architect 测定法<430nmol/L）的阈值。从一家医院的门诊患者数据中得出的标准在其他门诊和住院验证队列中进行了测试。
清晨（8am-12pm）血清皮质醇<275nmol/L 可识别出低刺激的皮质醇，其敏感性为 96.2%。对于下午（12pm-6pm）样本，<250nmol/L 的截止值达到了 96.1%的敏感性。当将标准应用于验证队列中的门诊患者的清晨和下午样本时，敏感性得以维持。对于住院患者，仅在清晨样本中该测试具有足够的敏感性。
单次测量血清皮质醇有可能显著减少在肾上腺功能不全的检查中对动态测试的需求，无论是在清晨还是下午的门诊诊所中，还是在住院患者的清晨样本中。
