Impaired osmoregulation in anorexia nervosa: review of the literature.

BACKGROUND: Anorexia nervosa (AN) is a serious eating disorder associated with numerous medical complications, including alterations in water balance and impaired osmoregulation.
OBJECTIVE: The aim of this paper is to review the evidence-based literature and discuss the potential pathophysiological mechanisms of impaired osmoregulation observed in patients with AN. MAIN DATA: Although limited, the evidence suggests that the pathophysiological mechanisms causing impaired osmoregulation in AN is multifactorial and includes abnormalities in osmoregulation of vasopressin, intrinsic renal defects and the influence of antidepressants often used in the treatment of patients with AN. Physicians treating patients with AN should be aware of this complication and the possible multifactorial etiology contributing to this medical complication.