Ramirez G, Gomez-Sanchez C, Meikle W A, Jubiz W
Arch Intern Med. 1982 Aug;142(8):1448-52.
Several alterations are present in the hypothalamic hypophyseal regulation of many hormones in patients with chronic renal failure. Evaluation of the hypothalamic hypophyseal adrenal axis in these groups of patients demonstrated normal levels of plasma cortisol. Dexamethasone suppression is abnormal after administration of 1 mg of oral dexamethasone, but normal after 3 mg. Dexamethasone blood levels were lower than the control after administration of 1 mg of oral dexamethasone. A dexamethasone metabolic clearance showed a similar half-life between the patients and controls. Oral absorption study showed poor absorption of the drug. Therefore, there is a problem of gastrointestinal absorption producing the abnormal dexamethasone suppression test in patients with renal failure. Results of metyrapone tests were normal. Corticotropin stimulation tests elicited a normal response. Insulin-induced hypoglycemia does not produce an increment in plasma cortisol or adrenocorticotropic hormone levels.
慢性肾功能衰竭患者下丘脑垂体对多种激素的调节存在多种改变。对这些患者组的下丘脑垂体肾上腺轴评估显示血浆皮质醇水平正常。口服1毫克地塞米松后地塞米松抑制异常，但3毫克后正常。口服1毫克地塞米松后地塞米松血药浓度低于对照组。地塞米松代谢清除率显示患者和对照组之间半衰期相似。口服吸收研究显示药物吸收不良。因此，存在胃肠道吸收问题导致肾衰竭患者地塞米松抑制试验异常。甲吡酮试验结果正常。促肾上腺皮质激素刺激试验引发正常反应。胰岛素诱导的低血糖不会使血浆皮质醇或促肾上腺皮质激素水平升高。
