The use of copeptin, the stable peptide of the vasopressin precursor, in the differential diagnosis of sodium imbalance in patients with acute diseases

Sodium imbalance is common in-hospital electrolyte disturbance and is largely related to inequalities in water homeostasis. An important mechanism leading to dysnatraemic disorders is inadequately secreted plasma arginine vasopressin (AVP). Unfortunately, AVP measurement is cumbersome and not reliable. Copeptin is secreted in an equimolar ratio to AVP and is a promising marker in the differential diagnosis of hyponatraemia and possibly hypernatraemia in stable hospitalised patients. This study assessed copeptin concentrations in sick patients with serum sodium imbalance of different aetiology on admission to the emergency department.