Assessing adrenal function in primary care settings with a single sample subcutaneous glucagon test

OBJECTIVE: To test the efficacy of the low-dose glucagon test in assessing adrenal gland function. STUDY DESIGN: Subcutaneous glucagon was used to assess the hypothalamo-pituitary-adrenal gland (HPA) axis in 215 healthy children. Concordance of this test with the low-dose intravenous ACTH test was established for 42 children. Glucagon testing was conducted for 150 minutes after subcutaneous glucagon administration and for 30 minutes after 1 microg intravenous ACTH. RESULTS: Mean peak serum cortisol concentrations were 22.4 +/- 0.6 microg/dL (SEM) after subcutaneous glucagon and 20.0 +/- 0.6 microg/dL after intravenous ACTH. Specificity of 95% was found at peak cortisol concentrations of 9.5 and 12.5 microg/dL for the glucagon and ACTH tests, respectively. Concordance between the glucagon and ACTH tests was 90.5%. CONCLUSIONS: The glucagon test was found to be as good a test of the HPA axis as the ACTH test and had a 90.5% concordance with it. The ease of performing the glucagon test, namely, obtaining a single sample of blood 150 minutes after the subcutaneous administration of glucagon, makes it a useful method of assessing the HPA axis in primary care settings.