POMC and Adrenal insufficiency: An early morning serum cortisol levels <3 mcg/dL (80 nmol/L) strongly suggests adrenal insufficiency, whereas levels >15 mcg/dL (415 nmol/L) predicts a normal response of serum cortisol to ACTH stimulation test (Hagg et al. 1987; Le Roux et al. 2002).