Hypothalamic-pituitary-adrenal axis activity in patients with primary polydipsia compared to healthy controls.

Objective: Primary polydipsia is characterized by excessive fluid intake which may suppress vasopressin levels. It is speculated that suppressed vasopressin levels lead to a dysregulated hypothalamic-pituitary-adrenal (HPA) axis as vasopressin co-modulates the HPA axis. However, data are contradictory.