内分泌
词汇介绍
拓展阅读
解析
dexamethasone 英/,deksə'meθəsəʊn; -zəʊn/ 美 /,dɛksə'mɛθə,son; ,dɛksə'mɛθə,zon/
释 义 n. [药] 地塞米松；氟美松（抗炎药）
例 句 Purpose To study the permeability of dexamethasone through cryopreserved amniotic membrane. 目的研究冷冻保存羊膜对地塞米松的通透性。
suppression 英 /səˈpreʃn/ 美 /səˈpreʃn/
释 义 n. 抑制；镇压；[植] 压抑
同根词 suppressed adj. 抑制的，发育不全的
suppressant n. 抑制药
suppressed v. 镇压，禁止
suppress vt. 抑制；镇压；废止
例 句 Because of the great cause of this suppression of the weak sentiments .因为伟大的事业抑制了这种软弱的感情。
test 英 /test/
释 义 n. 测验，考查；测试；检验；化验
v. 测验；化验，检查；试验，测试；考验
例 句 Please don't, if you are up here, become complacent because a month from now we will have another test.如果你考得不错的话，请不要自满,因为在一个月后我们将还有一次测试。
概述
概述
地塞米松抑制试验（DST）是通过注射不同剂量地塞米松测量功能皮质醇水平以测量肾上腺功能的实验。它通常用于诊断库欣综合症，地塞米松是一种外源性类固醇，可向垂体提供负反馈，从而抑制促肾上腺皮质激素（ACTH）的分泌。
过程
一般过程：
一夜小剂量：晚上11点服用1毫克的地塞米松，第二天早上8点，医疗保健人员会抽取血液进行皮质醇测量。
隔夜大剂量：提供者将在测试的早晨测量患者的皮质醇，然后，在晚上11点接受8毫克地塞米松，第二天早上8点，将抽血进行皮质醇测量。
较少使用的过程：
标准低剂量尿液：在3天内收集尿液（储存在24小时收集容器中）以测量皮质醇，在第2天，每6小时口服一次低剂量（0.5 mg）地塞米松，持续48小时。
标准大剂量：收集3天的尿液（储存在24小时的收集容器中），以测量皮质醇，在第2天，每6小时口服一次高剂量（2 mg）地塞米松，持续48小时。
正常结果
低剂量：隔夜：上午8点血浆皮质醇低于每分升1.8微克（mcg/dL）或每升50纳摩尔（nmol/L）；标准：第3天尿游离皮质醇低于每天10微克（mcg /天）或280 nmol / L。
高剂量：一夜之间，血浆皮质醇减少幅度超过50%。
标准剂量：尿中游离皮质醇减少超过90%。
异常结果
低剂量试验的异常反应可能意味着皮质醇释放异常（库欣综合征）。这可能是由于：产生皮质醇的肾上腺肿瘤、产生ACTH的垂体瘤、产生ACTH（异位库欣综合征）的肿瘤。
高剂量试验可帮助从其他原因中判断垂体原因（库欣病）。ACTH血液检查也可能有助于确定皮质醇升高的原因。
The Very Low-Dose Dexamethasone Suppression Test in the General Population: A Cross-Sectional Study
复制标题
普通人群的极低剂量地塞米松抑制试验: 一项横断面研究
发表时间：2016-11-01
影响指数：2.8
作者： Nese Direk
期刊：PLoS One
The hypothalamic-pituitary-adrenal (HPA) axis controls the stress response in the body. To explain the relation between diurnal HPA axis functioning and metabolic or stress-related disorders in large cohorts of healthy persons, researchers relied on single morning blood measures or used repeated saliva sampling. Different measures of the HPA axis such as cortisol awakening response, diurnal decline and total cortisol exposure over the day have been assessed using mostly saliva. More recently, cortisol assessment in hair became possible. In contrast, negative feedback of the HPA axis is rarely tested in non-clinical studies. In clinical populations, the negative feedback of the HPA axis is assessed by a dexamethasone suppression test (DST) requiring oral administration of a dose of dexamethasone. Cortisol secretion after dexamethasone intake is typically suppressed. A non-suppression indicates hypercortisolemia but DST proved very difficult to implement in population-based studies. The DST was originally designed to diagnose patients with Cushing’s Syndrome using 1 mg or higher doses of dexamethasone with a cut-off value for the plasma cortisol to distinguish between non-suppressors and suppressors. A dose of 1 mg in the conventional DST fully suppresses the HPA axis in most persons from a non-clinical population. Furthermore, the traditional “black and white” outcome definition of the negative feedback of the HPA axis masks any variation across the continuum of HPA axis reactivity. To this aim, cut-points were defined for the conventional DST, which relies on plasma cortisol to define suppression. In this population-based study, we tested the determinants of the negative feedback of the HPA axis with a very low-dose DST (0.25 mg) and assessed the outcome (suppression) continuously. Different determinants of the suppression or non-suppression after DST have been explored in the last decades. Over the years, the DST became perhaps the most common function test in clinically depressed persons. However, like in other psychiatric disorders including post-traumatic stress disorders, anxiety disorders, eating disorders, psychosis, personality traits, results of this test are inconsistent.
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