Papanicolaou D A, Yanovski J A, Cutler G B, Chrousos G P, Nieman L K
Developmental Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
J Clin Endocrinol Metab. 1998 Apr;83(4):1163-7. doi: 10.1210/jcem.83.4.4733.
Cushing's syndrome (CS) may be difficult to distinguish from pseudo-Cushing states (PCS) based on physical findings or urinary glucocorticoid excretion. As the lack of diurnal variation in serum cortisol is characteristic of CS, we studied whether diurnal cortisol determinations could discriminate CS from PCS. Two hundred and sixty-three patients were evaluated: 240 had CS, and 23 had PCS. Urine was collected for 24 h for measurement of cortisol and 17-hydroxycorticosteroids (17OHCS). Blood was drawn at 2300, 2330, 0000, 0030, and 0100 h and at 0600, 0630, 0700, 0730, and 0800 h the next morning for serum cortisol determination. The main outcome measure was the sensitivity of these parameters for the diagnosis of CS at 100% specificity. A midnight cortisol value greater than 7.5 microg/dL correctly identified 225 of 234 patients with CS and all PCS patients. This sensitivity (96%) was superior to that obtained for any other measure, including urinary cortisol (45%), 17OHCS (22%), any other individual cortisol time point (10-92%), the morning (23%) or the evening (93%) cortisol mean, and the ratio (11%) of morning to evening values. We conclude that at 100% specificity, a single serum cortisol value above 7.5 microg/dL at midnight discriminates CS from PCS with higher sensitivity than 24-h urinary cortisol or 17OHCS, or other individual or combined measures of serum cortisol.
基于体格检查结果或尿糖皮质激素排泄情况，库欣综合征（CS）可能难以与假性库欣状态（PCS）相区分。由于血清皮质醇缺乏昼夜变化是CS的特征，我们研究了昼夜皮质醇测定能否区分CS与PCS。对263例患者进行了评估：240例患有CS，23例患有PCS。收集24小时尿液以测定皮质醇和17-羟皮质类固醇（17OHCS）。于23:00、23:30、0:00、0:30和1:00时以及次日早晨06:00、06:30、07:00、07:30和08:00时采集血液以测定血清皮质醇。主要结局指标是这些参数在100%特异性时对CS诊断的敏感性。午夜皮质醇值大于7.5μg/dL可正确识别234例CS患者中的225例以及所有PCS患者。这种敏感性（96%）优于其他任何指标，包括尿皮质醇（45%）、17OHCS（22%）、任何其他单个皮质醇时间点（10%-92%）、早晨（23%）或晚上（93%）的皮质醇均值以及早晨与晚上值的比值（11%）。我们得出结论，在100%特异性时，午夜血清皮质醇值高于7.5μg/dL可将CS与PCS区分开来，其敏感性高于24小时尿皮质醇或17OHCS，或血清皮质醇的其他单个或综合指标。
