[Extended ACTH rapid test for differentiation of primary and secondary adrenal insufficiency]

In 30 resting normal persons, 5 ambulant normal persons and 3 patients with disorders of the pituitary-adrenal-system before and 30 minutes after intravenous injection of 0,25 mg synthetic adrenocorticotrophin (tetracosactid, Synacthen) plasma cortisol and aldosterone levels were evaluated. The evaluation of the corticoids was continued over 240 minutes in intervals of 30 minutes. The basal cortisol and aldosterone levels of the resting normal persons and ambulant persons ordinarily doubled 30 minutes after ACTH application. The plasma cortisol level of a steroid-treated patient with lupus erythematodes disseminatus rose subnormally but his aldosterone level increased normally. 2 patients with untreated hypopituitarism had subnormal plasma cortisol and normal aldosterone responses after ACTH administration. In contrast with patients with primary adrenal insufficiency, whose plasma aldosterone levels fail to rise, patients with secondary adrenal insufficiency had normal corticotrophin-stimulated aldosterone increments. Thus the extended ACTH test can be useful in differential diagnosis of primary and secondary adrenal insufficiency.