EVALUATION OF 3 ACUTE TESTS OF HYPOTHALAMIC-PITUITARY-ADRENAL FUNCTION

Three acute tests of hypothalamic-pituitary-adrenal (HPA) function have been compared in a group of 44 normal subjects and 140 patients with disease of the HPA axis. The three procedures (pyrogen test, lysine-vasopressin test and insulin tolerance test) caused similar increments of plasma cortisol in normal subjects, with good cross-reliability. In the patient group cross-reliability was poor and several types of discordant responses were found. The results suggest that lysine-vasopressin does not act directly on the anterior pituitary in man. The criteria for normal responses to the tests are discussed in detail. It is concluded that in the assessment of HPA function no test has any significant advantage. The practical significance of impaired or absent responses in relation to other types of stress is not fully understood. © 1969.