eMedicine Specialties > Endocrinology > Pituitary Gland

Diabetes Insipidus: Differential Diagnoses & Workup

Author: Michael Cooperman, MD, Clinical Associate Professor of Endocrinology, Temple University; Chair, Department of Internal Medicine, Division of Endocrinology, Jeanes Hospital
Contributor Information and Disclosures

Updated: Sep 25, 2009

Differential Diagnoses

Diabetes Mellitus, Type 1

Other Problems to Be Considered

Psychogenic polydipsia
Osmotic diuresis

Workup

Laboratory Studies

  • The diagnosis of diabetes insipidus (DI) is often made clinically, while the laboratory tests provide confirmation. Perform testing with the patient maximally dehydrated as tolerated, that is, at a time when ADH release would be highest and urine would be most concentrated. Ruling out secondary causes, such as diabetes mellitus, is also important.
  • The clinician should measure serum electrolytes and glucose, urine specific gravity, urinary sodium, simultaneous serum and urine osmolality, and ADH levels. A urine specific gravity of 1.005 or less and a urine osmolality less than 200 mOsm/kg is the hallmark of diabetes insipidus. Random plasma osmolality generally is greater than 287 mOsm/kg.
  • The water deprivation test (ie, Miller-Moses test), a semiquantitative test to ensure adequate dehydration and maximal stimulation of ADH for diagnosis, is performed in ambiguous clinical circumstances, typically with more chronic forms of diabetes insipidus. 
    • The extent of deprivation is usually limited by the patient's thirst or by any significant drop in blood pressure or related clinical manifestation of dehydration.
    • With mild polyuria, water deprivation can begin the night before the test. With severe polyuria, water restriction is carried out during the day to allow close observation.
    • All water intake is withheld and urine osmolality and body weight are measured hourly. When 2 sequential urine osmolalities vary by less than 30 mOsm or if the weight decreases by more than 3%, 5 U of aqueous vasopressin is administered subcutaneously. A final urine specimen is obtained 60 minutes later for osmolality measurement.
    • In healthy individuals, water deprivation leads to a urine osmolality that is 2-4 times greater than plasma osmolality. Administration of vasopressin results in less than 9% increment in urine osmolality. The time required to achieve maximal urine concentration ranges from 4-18 hours.
    • In complete central diabetes insipidus, testing reveals minimal ADH levels and activity, with failure of the urine to be concentrated despite excessively concentrated serum. In response to exogenous vasopressin, urine osmolality increases by more than 50%.
    • Patients with nephrogenic diabetes insipidus have a normal to elevated serum ADH level and failure of the kidney to respond to exogenous ADH during the water deprivation test.

Imaging Studies

  • Brain MRI
  • Pituitary MRI - T1-weighted images of the healthy posterior pituitary yield a hyperintense signal. In patients with central diabetes insipidus, this signal is absent, except in the rare familial form of central diabetes insipidus.

More on Diabetes Insipidus

Overview: Diabetes Insipidus
Differential Diagnoses & Workup: Diabetes Insipidus
Treatment & Medication: Diabetes Insipidus
Follow-up: Diabetes Insipidus
References
Further Reading
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References

  1. Earley LE, Orloff J. The mechanism of antidiuresis associated with the administration of hydrochlorothiazide to patients with vasopressin-resistant diabetes insipidus. J Clin Invest. Nov 1962;41(11):1988-97.

  2. Kristof RA, Rother M, Neuloh G, et al. Incidence, clinical manifestations, and course of water and electrolyte metabolism disturbances following transsphenoidal pituitary adenoma surgery: a prospective observational study. J Neurosurg. Feb 6 2009;[Medline].

  3. Seckl J, Dunger D. Postoperative diabetes insipidus. BMJ. Jan 7 1989;298(6665):2-3. [Medline].

  4. Hadjizacharia P, Beale EO, Inaba K, et al. Acute diabetes insipidus in severe head injury: a prospective study. J Am Coll Surg. Oct 2008;207(4):477-84. [Medline].

  5. Spanakis E, Milord E, Gragnoli C. AVPR2 variants and mutations in nephrogenic diabetes insipidus: review and missense mutation significance. J Cell Physiol. Dec 2008;217(3):605-17. [Medline].

  6. Hedrich CM, Zachurzok-Buczynska A, Gawlik A, et al. Autosomal dominant neurohypophyseal diabetes insipidus in two families. Molecular analysis of the vasopressin-neurophysin II gene and functional studies of three missense mutations. Horm Res. 2009;71(2):111-9. [Medline].

  7. Richardson DW, Robinson AG. Desmopressin. Ann Intern Med. Aug 1985;ID - NIH5M01(2):228-39. [Medline].

  8. Vande Walle J, Stockner M, Raes A, et al. Desmopressin 30 years in clinical use: a safety review. Curr Drug Saf. Sep 2007;2(3):232-8. [Medline].

  9. Ausiello JC, Bruce JN, Freda PU. Postoperative assessment of the patient after transsphenoidal pituitary surgery. Pituitary. 2008;11(4):391-401. [Medline].

  10. Charmandari E, Brook CG. 20 years of experience in idiopathic central diabetes insipidus [letter]. Lancet. Jun 26 1999;353(9171):2212-3. [Medline].

  11. Czernichow P, Robinson AG. Diabetes insipidus in man. Frontiers of Hormone Research. 1985;13-24.

  12. Pivonello R, De Bellis A, Faggiano A, et al. Central diabetes insipidus and autoimmunity: relationship between the occurrence of antibodies to arginine vasopressin-secreting cells and clinical, immunological, and radiological features in a large cohort of patients with central diabetes insipidus of known and unknown etiology. J Clin Endocrinol Metab. Apr 2003;88(4):1629-36. [Medline].

  13. Robertson GL. Diagnosis of diabetes insipidus. Frontiers of Hormone Research. 1985;13:176-89.

  14. Rose BD. Clinical Physiology of Acid-Base and Electrolyte Disorders. 4th ed. New York, NY:. McGraw-Hill;1994:698-720.

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Further Reading

Related eMedicine topics:
Diabetes Insipidus [Pediatrics: General Medicine]
Hypernatremia [Emergency Medicine]
Hypernatremia [Nephrology]
Hypernatremia [Pediatrics: Cardiac Disease and Critical Care Medicine]
Lithium Nephropathy
Pituitary Disease and Pregnancy

Clinical guidelines:
 ACR Appropriateness Criteria® neuroendocrine imaging. American College of Radiology - Medical Specialty Society. 1999 (revised 2008). 11 pages. NGC:007007

Clinical trials:
Copeptin in the Diagnosis and Differential Diagnosis of Diabetes Insipidus. The CoSIP-Study

Pharmacologic Treatment of Congenital Nephrogenic Diabetes Insipidus

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Keywords

diabetes insipidus, antidiuretic hormone, ADH, DDAVP, desmopressin, vasopressin, diabetes urine, arginine vasopressin, central diabetes insipidus, nephrogenic diabetes insipidus, polyuria, polydipsia, hypernatremia, dehydration, craniopharyngioma, pineal tumors, primary intracranial tumors, idiopathic diabetes insipidus

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Contributor Information and Disclosures

Author

Michael Cooperman, MD, Clinical Associate Professor of Endocrinology, Temple University; Chair, Department of Internal Medicine, Division of Endocrinology, Jeanes Hospital
Michael Cooperman, MD is a member of the following medical societies: Alpha Omega Alpha, American Association of Clinical Endocrinologists, and Endocrine Society
Disclosure: Nothing to disclose.

Medical Editor

Frederick H Ziel, MD, Associate Professor of Medicine, David Geffen School of Medicine at UCLA; Physician-In-Charge, Endocrinology/Diabetes Center, Director of Medical Education, Kaiser Permanente Woodland Hills; Chair of Endocrinology, Co-Chair of Diabetes Complete Care Program, Southern California Permanente Medical Group
Frederick H Ziel, MD is a member of the following medical societies: American Association of Clinical Endocrinologists, American College of Endocrinology, American College of Physicians, American College of Physicians-American Society of Internal Medicine, American Diabetes Association, American Federation for Medical Research, American Medical Association, American Society for Bone and Mineral Research, California Medical Association, Endocrine Society, and International Society for Clinical Densitometry
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Romesh Khardori, MD, Chief, Division of Endocrinology, Metabolism and Molecular Medicine, Professor, Department of Internal Medicine, Southern Illinois University School of Medicine
Romesh Khardori, MD is a member of the following medical societies: American Association of Clinical Endocrinologists, American College of Physicians, American Diabetes Association, American Federation for Medical Research, American Medical Association, American Society of Andrology, Endocrine Society, and Illinois State Medical Society
Disclosure: Nothing to disclose.

CME Editor

Mark Cooper, MBBS, PhD, FRACP, Head, Diabetes & Metabolism Division, Baker Heart Research Institute, Professor of Medicine, Monash University
Disclosure: Nothing to disclose.

Chief Editor

George T Griffing, MD, Professor of Medicine, St Louis University School of Medicine
George T Griffing, MD is a member of the following medical societies: American Association for the Advancement of Science, American College of Medical Practice Executives, American College of Physician Executives, American College of Physicians, American Diabetes Association, American Federation for Medical Research, American Heart Association, Central Society for Clinical Research, Endocrine Society, International Society for Clinical Densitometry, and Southern Society for Clinical Investigation
Disclosure: Nothing to disclose.

 
 
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