Reliability of the 30-Minute ACTH Test in Assessing Hypothalamic-Pituitary-Adrenal Function

Abstract
An insulin hypoglycemia test and a 30-min ACTH test were performed in 90 patients with proved or suspected hypothalamic-pituitary-adrenal hypofunction and in 10 normal subjects. The peak plasma cortisol concentration during hypoglycemia and the cortisol concentration at 30 min after injection of 250 μg corticotropin1–24 were compared. A very close correlation (r = 0.92) was found between the two concentrations, with no major discrepancy in any case. It is concluded that the short ACTH test accurately reflects the integrated hypothalamic-pituitary-adrenal function, as assessed by the insulin hypoglycemia test.