Stress-Induced Cortisol Release in Hypothalamic Hypoadrenalism

Abstract

A 52-year-old woman experienced hypoadrenalism (mean 8 AM plasma cortisol level, 3.7 microgram/dL) after hypothalamic surgery and radiotherapy for craniopharyngioma. Despite low plasma adrenocorticotropic hormone levels (less than 25 pg/mL), absent diurnal variation of the plasma cortisol level, and subnormal urinary 17-hydroxycorticosteroid response to metyrapone, she had normal plasma cortisol responses to insulin-induced hypoglycemia and to administration of vasopressin or synthetic adrenocorticotropic hormone. Stress-induced cortical release may be preserved despite notable abnormalities in regulation of cortisol secretion by diurnal and feedback-mediated mechanisms.