Fiad T M, Kirby J M, Cunningham S K, McKenna T J
Department of Endocrinology and Diabetes Mellitus, St Vincent's Hospital, Dublin, Ireland.
Clin Endocrinol (Oxf). 1994 May;40(5):603-9. doi: 10.1111/j.1365-2265.1994.tb03011.x.
The ACTH stimulation test examines adrenal responsiveness but may not examine the entire hypothalamic-pituitary-adrenal (HPA) axis and requires parenteral administration. The cortisol response to hypoglycaemia provides an index of activity of the entire HPA axis but is demanding for patients and medical staff. The aim of the present study was to examine the performance of the overnight single-dose metyrapone test as it provides a simple alternative test for HPA axis function.
Audit of the overnight metyrapone test performed in one centre between 1979 and 1991.
Three hundred and ninety-eight patients underwent 576 tests. Comparisons between the responses to metyrapone and the ACTH stimulation test and of the responses to metyrapone and insulin induced hypoglycaemia test were possible in 87 and 17 patients respectively.
Following the midnight administration of metyrapone tablets, 30 mg/kg orally, blood samples were obtained between 0800 and 0930 h for radioimmunoassay of both 11-deoxycortisol and cortisol.
Five hundred and seventy-six metyrapone tests were performed on 398 patients with no serious side-effects encountered. Adrenal insufficiency was diagnosed in 105 patients. Of these, 18 had a primary adrenal disorder and 87 had a disorder of the hypothalamic-pituitary unit. One hundred per cent concordance between the metyrapone, the ACTH and the hypoglycaemia test was seen in patients with primary adrenal insufficiency. In 19 patients with secondary adrenal insufficiency, who underwent both the metyrapone and the ACTH tests, discord between these two tests was observed in 10 patients (53%). Nine of these patients demonstrated a normal response to ACTH and a subnormal response to metyrapone. In only one patient was an abnormal cortisol response to ACTH associated with a normal response to metyrapone. In contrast, in 17 patients discord between the metyrapone and the hypoglycaemia test was seen in only 1 patient who demonstrated a normal response to the metyrapone test and a subnormal response to hypoglycaemia.
Since the metyrapone test gives similar information about hypothalamic-pituitary axis function as does the hypoglycaemia test, we recommend the use of the overnight metyrapone test as a safe, simple and reliable index of the hypothalamic-pituitary axis integrity. The ACTH stimulation test should not be used for patients suspected of having secondary adrenal insufficiency.
促肾上腺皮质激素（ACTH）刺激试验可检测肾上腺反应性，但可能无法检测整个下丘脑 - 垂体 - 肾上腺（HPA）轴，且需要肠胃外给药。低血糖时皮质醇反应可反映整个HPA轴的活性，但对患者和医护人员要求较高。本研究旨在探讨过夜单剂量甲吡酮试验的性能，因为它为HPA轴功能提供了一种简单的替代检测方法。
对1979年至1991年在一个中心进行的过夜甲吡酮试验进行审计。
398例患者接受了576次检测。分别有87例和17例患者能够比较甲吡酮试验与ACTH刺激试验的反应以及甲吡酮试验与胰岛素诱导低血糖试验的反应。
午夜口服甲吡酮片，剂量为30mg/kg，于08:00至09:30采集血样，用于放射免疫法检测11 - 脱氧皮质醇和皮质醇。
对398例患者进行了576次甲吡酮试验，未出现严重副作用。105例患者被诊断为肾上腺功能不全。其中，18例为原发性肾上腺疾病，87例为下丘脑 - 垂体单位疾病。原发性肾上腺功能不全患者中甲吡酮试验、ACTH试验和低血糖试验结果的一致性为100%。19例继发性肾上腺功能不全患者同时接受了甲吡酮试验和ACTH试验，其中10例（53%）这两项试验结果不一致。这些患者中有9例对ACTH反应正常，对甲吡酮反应异常。只有1例患者对ACTH的皮质醇反应异常，而对甲吡酮反应正常。相比之下，17例患者中甲吡酮试验和低血糖试验结果不一致的仅1例，该患者对甲吡酮试验反应正常，对低血糖反应异常。
由于甲吡酮试验提供的关于下丘脑 - 垂体轴功能的信息与低血糖试验相似，我们建议将过夜甲吡酮试验作为下丘脑 - 垂体轴完整性的一种安全、简单且可靠的指标。对于怀疑有继发性肾上腺功能不全的患者，不应使用ACTH刺激试验。
