Department of Endocrinology, University of Duisburg-Essen, Hufelandstrasse 55, 45122 Essen, Germany.
Eur J Endocrinol. 2010 Mar;162(3):477-82. doi: 10.1530/EJE-09-0824. Epub 2009 Dec 8.
The glucagon stimulation test (GST) like the insulin tolerance test (ITT) stimulates both ACTH and GH secretion. However, there are limited data with modern assays on sensitivity and specificity for GST in comparison to ITT. The aim of this study was to evaluate the diagnostic utility of the GST for GH deficiency (GHD) and adrenal insufficiency (AI) in patients following pituitary surgery.
ITT and GST were performed within 7 days in 49 patients at least 3 months after transsphenoidal surgery. Serum GH and cortisol were measured by Immulite 2000 assay (Siemens AG). Receiver-operating characteristic (ROC) analysis was performed to identify the thresholds for GST.
In ITT, 18/49 cases were classified as AI. ROC analysis revealed a peak cortisol value >599 nmol/l in GST for adrenal sufficiency with 100% specificity and 32% sensitivity, and a peak cortisol <277 nmol/l with >95% specificity and 72% sensitivity for AI. Of the 49 subjects, 25 (51%) demonstrated levels between these cut-offs and could not be diagnosed by GST alone with sufficient accuracy. Regarding GHD, 21/49 cases were classified as insufficient by ITT. ROC analysis revealed a cut-off of 2.5 ng/ml with 95% sensitivity and 79% specificity. Of the 49 cases, seven (14%) were discordant in terms of defining GHD, with six subjects being treated for GHD according to GST although being sufficient in ITT.
In our prospective series of patients with pituitary disease, GST is a potential alternative test for the assessment of GH reserve, but is a poor test for ACTH reserve. Test-specific cut-offs should be applied to avoid misinterpretation.
胰高血糖素刺激试验（GST）与胰岛素耐量试验（ITT）一样，可同时刺激 ACTH 和 GH 的分泌。然而，与 ITT 相比，现代检测方法对 GST 的敏感性和特异性的数据有限。本研究旨在评估 GST 在垂体手术后患者中诊断 GH 缺乏症（GHD）和肾上腺功能不全（AI）的诊断效用。
49 例患者在经蝶窦手术后至少 3 个月内行 GST 和 ITT，两者在 7 天内进行。使用 Immulite 2000 测定法（西门子公司）检测血清 GH 和皮质醇。进行了接受者操作特征（ROC）分析，以确定 GST 的阈值。
在 ITT 中，18/49 例被分类为 AI。ROC 分析显示，GST 中峰值皮质醇>599 nmol/l 时为肾上腺功能正常，特异性为 100%，敏感性为 32%；峰值皮质醇<277 nmol/l 时，特异性>95%，敏感性为 72%，用于 AI。在 49 名受试者中，有 25 名（51%）处于这些截止值之间，仅靠 GST 无法准确诊断。在 49 例中，21 例（43%）根据 ITT 被分类为不足。ROC 分析显示，截断值为 2.5ng/ml，敏感性为 95%，特异性为 79%。在 49 例中，有 7 例（14%）在定义 GHD 方面存在差异，6 例根据 GST 被诊断为 GHD，但在 ITT 中是足够的。
在我们的垂体疾病患者前瞻性系列中，GST 是评估 GH 储备的潜在替代试验，但对 ACTH 储备的检测较差。应应用特定的检测截断值，以避免误解。
Zotero 插件