Copeptin in critical illness

review on copeptin, the C-terminal fragment of the pro-vasopresin peptide (CTproAVP), as a surrogate biomarker of arginine vasopressin [1]. Copeptin is co-released from the hypothalamus in an equimolar ratio with the hypotha-lamic stress hormone vasopressin, and hence secretion is activated not only by changes in plasma osmolality and circulating blood volume, but also by stress and inflam-matory states. Copeptin reflects the stress response during critical illness. Its plasmatic concentration has been associated with mortality in several acute disease states. The acute-phase response to critical illness is characterized by an abrupt and massive release of stress hormones, includ-ing adrenocorticotropic hormone and cortisol, catechol-amines, vasopressin, glucagon, and growth hormon