Avgerinos P C, Nieman L K, Oldfield E H, Cutler G B
Developmental Endocrinology Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
Clin Endocrinol (Oxf). 1996 Oct;45(4):483-91. doi: 10.1046/j.1365-2265.1996.8170827.x.
We wished to develop optimal criteria for interpreting the single-dose overnight metyrapone test and to compare the diagnostic efficiency of the overnight and the standard 6-dose metyrapone tests for the differential diagnosis of ACTH-dependent Cushing's syndrome.
Retrospective pilot study based on all patients who completed both metyrapone tests and whose diagnoses were subsequently confirmed surgically.
Sixty-three patients, 57 with pituitary tumours and 6 with ectopic ACTH syndrome, were studied.
The sensitivity and specificity were determined using stimulation of plasma 11-deoxycortisol and suppression of plasma cortisol as endpoints for the overnight test and stimulation of urine 17-hydroxysteroid and plasma 11-deoxycortisol as endpoints for the standard test. The lest response that gave the highest sensitivity for the diagnosis of Cushing's disease, with 100% specificity, was determined for each test endpoint.
Both the stimulation of plasma 11-deoxycortisol and the suppression of plasma cortisol were expressed as the ratio of the post-metyrapone value to baseline. A plasma 11-deoxycortisol ratio > than 220 or a plasma cortisol ratio > 0.6 was associated with 100% specificity for diagnosis of Cushing's disease by the overnight test. When these two criteria were combined, the sensitivity was 65%, which was significantly higher than that obtained using either steroid alone: 42% for both plasma 11-deoxycortisol and plasma cortisol. The sensitivity of 65% for the overnight test, at 100% specificity, was nearly identical to that of the standard test in the same patients: 67% for the combined criterion of > 70% stimulation of urine 17-hydroxysteroid or > 480-fold increase of plasma 11-deoxycortisol. When the criteria for both the overnight and standard tests were combined, the sensitivity increased to 84%, which was higher than that obtained using the criteria for either test alone (P < 0.02).
The single-dose overnight metyrapone test, which can be performed in 24 hours and which avoids the disadvantages associated with timed urine collections, has a nearly identical sensitivity (for a specificity of 100%) as the 6-dose standard metyrapone test for the diagnosis of Cushing's disease. Furthermore, the diagnostic performance of a criterion that combines the results of both tests is significantly better than the best criterion for either test alone.
我们希望制定出解释单剂量过夜美替拉酮试验的最佳标准，并比较过夜美替拉酮试验与标准6剂量美替拉酮试验对促肾上腺皮质激素（ACTH）依赖性库欣综合征鉴别诊断的诊断效率。
基于所有完成两种美替拉酮试验且后续诊断经手术证实的患者进行回顾性初步研究。
研究了63例患者，其中57例患有垂体肿瘤，6例患有异位ACTH综合征。
以过夜试验中血浆11 - 脱氧皮质醇的刺激和血浆皮质醇的抑制为终点，以及标准试验中尿17 - 羟类固醇的刺激和血浆11 - 脱氧皮质醇的刺激为终点来确定敏感性和特异性。针对每个试验终点，确定对库欣病诊断具有最高敏感性且特异性为100%的最低反应值。
血浆11 - 脱氧皮质醇的刺激和血浆皮质醇的抑制均表示为美替拉酮给药后值与基线值的比值。过夜试验中，血浆11 - 脱氧皮质醇比值>220或血浆皮质醇比值>0.6与库欣病诊断的100%特异性相关。当将这两个标准结合时，敏感性为65%，显著高于单独使用任何一种类固醇时的敏感性：血浆11 - 脱氧皮质醇和血浆皮质醇单独使用时均为42%。过夜试验在特异性为100%时的65%敏感性与同一患者中标准试验的敏感性几乎相同：尿17 - 羟类固醇刺激>70%或血浆11 - 脱氧皮质醇增加>480倍的联合标准的敏感性为67%。当过夜试验和标准试验的标准结合时，敏感性提高到84%，高于单独使用任何一种试验的标准时的敏感性（P<0.02）。
单剂量过夜美替拉酮试验可在24小时内完成，避免了与定时收集尿液相关的缺点，对于库欣病的诊断，其敏感性（特异性为100%）与6剂量标准美替拉酮试验几乎相同。此外，将两种试验结果结合的标准的诊断性能明显优于单独使用任何一种试验的最佳标准。
