Altered hypothalamic-pituitary-adrenal responsiveness to dexamethasone-insulin tolerance test in active acromegaly.
Eight acromegalic patients showed a plasma cortisol (11-OHCS) rise after insulin hypoglycemia which was similar to that seen in control patients, with mean peak values (+/-SEM) of 23.2 +/- 3.5 mug/100 ml and 27.2 +/- 3.3 mug/100 ml, respectively. One mg of dexamethasone was given the evening prior to repeat insulin hypoglycemia (DEX-ITT). After dexamethasone, the control subjects showed a mean post hypoglycemic plasma 11-OHCS rise to 18.3 +/- 2.3 mug/100 ml. In contrast, acromegalic patients had a negligible rise is plasma 11-OHCS, despite a comparable degree of hypoglycemia. These data indicate that, in active acromegaly, abnormal hypothalamic-pituitary-adrenal suppressibility can be induced to  insulin hypoglycemia after dexamethasone.
D015062:11-Hydroxycorticosteroids / Q000097:blood; D000172:Acromegaly / Q000503:physiopathology*; D000311:Adrenal Glands / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology*; D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D003907:Dexamethasone; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007031:Hypothalamus / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology*; D007328:Insulin; D008297:Male; D008875:Middle Aged; D010902:Pituitary Gland / Q000187:drug effects / Q000503:physiopathology*; D013997:Time Factors
D015062:11-Hydroxycorticosteroids; D001786:Blood Glucose; D007328:Insulin; D003907:Dexamethasone; D006854:Hydrocortisone