Chapter 10 - Endocrinological diagnosis and replacement therapy for diabetes insipidus

Abstract

Diabetes insipidus is a disorder characterized by excretion of large amounts of hypotonic urine. Four entities have to be differentiated: central diabetes insipidus resulting from a deficiency of the hormone arginine vasopressin (AVP) in the pituitary gland or the hypothalamus, nephrogenic diabetes insipidus resulting from resistance to AVP in the kidneys, gestational diabetes insipidus resulting from an increase in placental vasopressinases, and finally primary polydipsia, which involves excessive intake of large amounts of water despite normal AVP secretion and action. Distinguishing between the different types of diabetes insipidus can be challenging and is done either by a water deprivation test or by hypertonic saline stimulation or arginine stimulation together with copeptin (or AVP) measurement. Furthermore a detailed medical history, physical examination, and imaging studies are needed to detect the etiology of diabetes insipidus. Treatment of diabetes insipidus or primary polydipsia depends on the underlying etiology and differs in central diabetes insipidus, nephrogenic diabetes insipidus, and primary polydipsia. This book chapter will primarily focus on diagnosis and treatment of central diabetes insipidus.