[Hypothalamic-hypophyseal-adrenocortical dysfunction in patients with anorexia nervosa (author's transl)]

Hypothalamic-pituitary-adrenocortical function was investigated in 14 patients with anorexia nervosa. Impaired suppression of plasma cortisol by dexamethasone was revealed. In 14 patients with anorexia nervosa, circadian rhythm of plasma cortisol, insulin tolerance test, rapid ACTH test and overnight dexamethasone suppression test were examined. Levels of plasma cortisol were higher than those in control subjects throughout the day, and normal circadian rhythm of plasma cortisol was not observed. Basal levels of plasma ACTH were within normal range. tthe response of plasma cortisol to insulin-induced hypoglycemia was lower than that in control subjects, while the response of plasma cortisol in rapid Acth test was normal. In overnight suppression tests, in which one mg dexamethasone was administered orally, 11 of 14 patients showed no suppression of plasma cortisol and 3 other patients showed incomplete suppression. Elevated levels of plasma cortisol and the absence of normal circadian rhythm in patients with anorexia nervosa and malnutrition have already been reported by other investigators, and these abnormalities were ascribed to the delayed half life of plasma cortisol due to impaired cortisol metabolism. However, according to our investigation, it is difficult to explain the failure of dexamethasone to suppress cortisol only by the delayed half life of plasma cortisol, and it is supposed that some kind of abnormal hypothalamic control is also involved.