AVP and Abdominal obesity: Several changes in the hypothalamic-pituitary-adrenal (HPA) axis of subjects with abdominal obesity have been described: changes in pulsatile secretion of adrenocorticotropic hormone (ACTH), increased cortisol secretion after laboratory stress tests, hyperresponsivity of the HPA axis to peptides such as the corticotropin-releasing hormone (CRH), associated or not with arginine vasopressin (AVP) (for references, see [10, 11]).