Diabetes insipidus (DI) is a disorder characterised by polydipsia, polyuria, and formation of inappropriately hypotonic (dilute) urine.
Two types exist: central DI, due to reduced synthesis or release of arginine vasopressin (AVP) from the hypothalamo-pituitary axis; and nephrogenic DI, due to renal insensitivity to AVP.
Recognised risk factors for central DI include pituitary surgery, craniopharyngioma, infiltrative pituitary stalk lesions, traumatic brain injury, subarachnoid haemorrhage, congenital hypothalamo-pituitary defects, autoimmune disorders, and Wolfram syndrome. Risk factors for nephrogenic DI include lithium therapy, chronic kidney disease, and chronic hypercalcaemia or hypokalaemia. Genetic mutations are responsible for inherited forms of both types.
Both types of DI may be associated with hypernatraemia, and this may present as a medical emergency.
Treatment goals are correction and stabilisation of water deficit and electrolyte balance, together with reduction in symptoms of excessive urinary water loss and thirst. In central DI, the synthetic AVP analogue desmopressin (DDAVP) is the treatment of choice. Nephrogenic DI is treated with an adequate fluid intake; salt restriction and diuretics may help reduce polyuria.
Diabetes insipidus is a metabolic disorder characterised by an absolute or relative inability to concentrate urine, resulting in the production of large quantities of dilute urine. It may result from an absolute or relative deficiency of arginine vasopressin (AVP), also known as antidiuretic hormone (ADH), which is produced by the hypothalamus and secreted via the posterior pituitary, or by resistance to its action within the renal collecting ducts. Clinically it manifests as polydipsia, polyuria, and hypotonic urine.
History and exam
Key diagnostic factors
- history of pituitary/hypothalamic disease
- family history/genetic mutations
- history of lithium therapy
- history of autoimmune disorders
- increased thirst/polydipsia
Other diagnostic factors
- signs of volume depletion
- non-specific central nervous system symptoms of hypernatraemia
- visual field defects
- focal motor deficits
- sensorineural deafness and visual failure
- skin lesions
- pituitary surgery
- pituitary stalk lesions
- traumatic brain injury
- congenital pituitary abnormalities
- autoimmune disease
- family history/genetic mutations
- subarachnoid haemorrhage
- renal sarcoidosis
- renal amyloidosis
- hypercalcaemia or hypokalaemia
- release of obstructive uropathy
- previous central nervous system infections
1st investigations to order
- urine osmolality
- serum osmolality
- serum glucose
- serum sodium
- serum potassium
- serum urea nitrogen
- serum calcium
- urine dipstick
- 24-hour urine collection for volume
- water deprivation test
- AVP (desmopressin) stimulation test
- hypertonic saline-stimulated test with measurement of copeptin
Investigations to consider
- cranial MRI (contrast-enhanced)
- genetic testing
- antithyroid peroxidase autoantibodies
- serum and cerebrospinal fluid alpha-fetoprotein and beta-human chorionic gonadotrophin
- serum growth hormone (GH)
- serum insulin-like growth factor 1 (IGF-1)
- provocative growth hormone (GH) tests
- serum LH
- serum follicle-stimulating hormone
- morning serum testosterone
- serum thyroid-stimulating hormone and triiodothyronine/thyroxine (T3/T4)
- morning serum cortisol and adrenocorticotrophic hormone (ACTH)
- serum prolactin
hypernatraemia at any stage
acute central DI
chronic central DI
Stephen Ball, FRCP, MBBS, PhD
Manchester University Foundation Trust
Hon. Professor of Medicine and Endocrinology
Manchester Academic Health Science Centre
SB declares that he has no competing interests.
Dr Stephen Ball wishes to gratefully acknowledge Dr Mark Sherlock and Dr Paul M. Stewart, previous contributors to this topic.
MS and PMS declare that they have no competing interests.
Janet Amico, MD
Professor of Medicine
Division of Endocrinology and Metabolism
University of Pittsburgh School of Medicine
At the time of peer review, JA received research grants from the National Institutes of Health, the Department of Veterans' Affairs, and the Department of Defense. We were made aware that Professor Amico is now deceased.
Christopher Thompson, MB ChB, MD, FRCPI, FRCP
Professor of Endocrinology
Department of Endocrinology
CT declares that he has no competing interests.
- Psychogenic polydipsia
- Diabetes mellitus
- Diuretic use
- ACR appropriateness criteria: neuroendocrine imaging
- Inpatient management of cranial diabetes insipidus
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