eMedicine Specialties > Pediatrics: General Medicine > Endocrinology

Diabetes Insipidus: Differential Diagnoses & Workup

Author: James CM Chan, MD, Professor of Pediatrics, University of Vermont College of Medicine; Director of Research, The Barbara Bush Children's Hospital, Maine Medical Center
Coauthor(s): Karl S Roth, MD, Professor and Chair, Department of Pediatrics, Creighton University School of Medicine
Contributor Information and Disclosures

Updated: Feb 6, 2009

Differential Diagnoses

Head Trauma
Medullary Cystic Disease
Sickle Cell Anemia

Other Problems to Be Considered

Histiocytosis X
Hypercalcemic nephropathy
Hypokalemic nephropathy
Interstitial nephritis
Posterior fossa tumor
Neurosurgical ablation of neurohypophysis
Psychogenic polydipsia
Water intoxication (excessive consumption)

Workup

Laboratory Studies

  • In assessing patients with suspected diabetes insipidus (DI), the urine specific gravity of the first morning urine is helpful in assessing renal ability to concentrate urine. Dilute urine with a relatively high serum sodium and osmolarity effectively establishes the diagnosis. The serum sodium may be as high as 170 mEq/L, while the serum osmolarity is greater than 300 mOsm/kg. Patients with prerenal azotemia present with severe dehydration.
  • In young infants, finding a distinction between normal and pathological inability to concentrate the urine may be difficult because infants generally exhibit a constitutional hyposthenuria.
  • The definitive diagnostic study is the water deprivation test, which can be used both to confirm the diagnosis and to distinguish between central diabetes insipidus (CDI) and nephrogenic diabetes insipidus (NDI) by response to a vasopressin analogue. The water deprivation test is performed as follows:
    • Obtain baseline urine and blood for osmolality and electrolytes. Deprive the patient of water after breakfast until significant dehydration occurs. Weigh the patient every 2 hours and limit dehydration to 2-5% loss of body weight.
    • Monitor urine specific gravity hourly; if the specific gravity is 1.014 or greater, terminate the test and obtain appropriate urine and blood specimens for osmolality. Limit water deprivation to 4 hours for infants and 7 hours for children. If polyuria persists, administer intranasal desmopressin (see Medication) and replace urine output with fluids. After 4 hours (2 h in infants), obtain urine and blood for osmolality.
    • The normal response to dehydration or desmopressin acetate (DDAVP) includes urine osmolality greater than 450 mOsm/kg, urine/serum osmolality greater than or equal to 1.5, and an increase in urine/serum osmolality from baseline of 1.0 or more. A normal response should be observed in central diabetes insipidus and psychogenic diabetes insipidus but not in nephrogenic diabetes insipidus.
  • An accurate 24-hour urine collection is important. The total urine output is high, and the number of osmoles excreted per day is small.
  • Serum potassium and calcium concentrations are important to exclude the possibility of polyuria secondary to hypokalemia or hypercalcemia, both of which interfere with renal concentrating mechanisms.

Imaging Studies

  • Cranial MRI can be used to exclude pituitary cysts, hypoplasia, and destruction secondary to mass lesions. Often, the bright spot that is thought to represent vasopressin-secreting neurons in the posterior pituitary is absent in central diabetes insipidus.

More on Diabetes Insipidus

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

  1. Bichet DG, Arthus MF, Lonergan M, et al. X-linked nephrogenic diabetes insipidus mutations in North America and the Hopewell hypothesis. J Clin Invest. Sep 1993;92(3):1262-8. [Medline]. [Full Text].

  2. Friedman E, Bale AE, Carson E, et al. Nephrogenic diabetes insipidus: an X chromosome-linked dominant inheritance pattern with a vasopressin type 2 receptor gene that is structurally normal. Proc Natl Acad Sci U S A. Aug 30 1994;91(18):8457-61. [Medline]. [Full Text].

  3. Wildin RS, Antush MJ, Bennett RL. Heterogeneous AVPR2 gene mutations in congenital nephrogenic diabetes insipidus. Am J Hum Genet. Aug 1994;55(2):266-77. [Medline].

  4. Faerch M, Christensen JH, Corydon TJ, et al. Partial nephrogenic diabetes insipidus caused by a novel mutation in the AVPR2 gene. Clin Endocrinol (Oxf). Mar 2008;68(3):395-403. [Medline].

  5. Alon U, Chan JC. Hydrochlorothiazide-amiloride in the treatment of congenital nephrogenic diabetes insipidus. Am J Nephrol. 1985;5(1):9-13. [Medline].

  6. Blackett PR, Seif SM, Altmiller DH, Robinson AG. Familial central diabetes insipidus: vasopressin and nicotine stimulated neurophysin deficiency with subnormal oxytocin and estrogen stimulated neurophysin. Am J Med Sci. Nov-Dec 1983;286(3):42-6. [Medline].

  7. Davies JH, Penney M, Abbes AP, et al. Clinical features, diagnosis and molecular studies of familial central diabetes insipidus. Horm Res. 2005;64(5):231-7. [Medline].

  8. Garofeanu CG, Weir M, Rosas-Arellano MP, et al. Causes of reversible nephrogenic diabetes insipidus: a systematic review. Am J Kidney Dis. Apr 2005;45(4):626-37.

  9. Leung AK, Robson WL, Halperin ML. Polyuria in childhood. Clin Pediatr (Phila). Nov 1991;30(11):634-40. [Medline].

  10. Libber S, Harrison H, Spector D. Treatment of nephrogenic diabetes insipidus with prostaglandin synthesis inhibitors. J Pediatr. Feb 1986;108(2):305-11. [Medline].

  11. Mulders SM, Bichet DG, Rijss JP, et al. An aquaporin-2 water channel mutant which causes autosomal dominant nephrogenic diabetes insipidus is retained in the Golgi complex. J Clin Invest. Jul 1 1998;102(1):57-66. [Medline]. [Full Text].

  12. Pivonello R, Colao A, DiSomma C, et al. Impairment of bone status in patients with central diabetes insipidus. J Clin Endocrinol Metab. Jul 1998;83(7):2275-80. [Medline]. [Full Text].

  13. Saborio P, Tipton GA, Chan JC. Diabetes insipidus. Pediatr Rev. Apr 2000;21(4):122-9; quiz 129. [Medline].

  14. Soylu A, Kasap B, Ogun N, et al. Efficacy of COX-2 inhibitors in a case of congenital nephrogenic diabetes insipidus. Pediatr Nephrol. Dec 2005;20(12):1814-7. [Medline].

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Further Reading

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Keywords

diabetes insipidus, DI, hypernatremia, thirst, polydipsia, dehydration, central diabetes insipidus, CDI, nephrogenic diabetes insipidus, NDI, failure to thrive, nocturia, fecalith, Wolfram syndrome, diabetes mellitus, optic atrophy, mental retardation, hypokalemia, hypercalcemia

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Contributor Information and Disclosures

Author

James CM Chan, MD, Professor of Pediatrics, University of Vermont College of Medicine; Director of Research, The Barbara Bush Children's Hospital, Maine Medical Center
James CM Chan, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American Association of University Professors, American Chemical Society, American Heart Association, American Medical Association, American Physiological Society, American Society for Bone and Mineral Research, American Society of Nephrology, American Society of Pediatric Nephrology, International Society of Nephrology, New York Academy of Sciences, Society for Experimental Biology and Medicine, and Southern Society for Pediatric Research
Disclosure: Nothing to disclose.

Coauthor(s)

Karl S Roth, MD, Professor and Chair, Department of Pediatrics, Creighton University School of Medicine
Karl S Roth, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Pediatrics, American College of Nutrition, American Pediatric Society, American Society for Clinical Nutrition, American Society of Nephrology, Association of American Medical Colleges, Medical Society of Virginia, New York Academy of Sciences, Sigma Xi, Society for Pediatric Research, and Southern Society for Pediatric Research
Disclosure: MDS Pharma Salary Employment

Medical Editor

Thomas A Wilson, MD, Professor of Clinical Pediatrics, Department of Pediatrics; Director of Pediatric Endocrinology, Division of Pediatric Endocrinology, Department of Pediatrics, State University of New York at Stony Brook
Thomas A Wilson, MD is a member of the following medical societies: Endocrine Society, Lawson-Wilkins Pediatric Endocrine Society, and Phi Beta Kappa
Disclosure: Nothing to disclose.

Pharmacy Editor

Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine
Disclosure: Pfizer Inc Stock Investment from financial planner; Avanir Pharma Stock Investment from financial planner ; WebMD Salary and stock Employment and investment from financial planner

Managing Editor

George P Chrousos, MD, FAAP, MACP, MACE, FRCP(London), Professor and Chair, First Department of Pediatrics, Athens University Medical School, Aghia Sophia Children's Hospital, Greece
George P Chrousos, MD, FAAP, MACP, MACE, FRCP(London) is a member of the following medical societies: American Academy of Pediatrics, American College of Endocrinology, American College of Physicians, American Pediatric Society, American Society for Clinical Investigation, Association of American Physicians, Endocrine Society, Lawson-Wilkins Pediatric Endocrine Society, and Society for Pediatric Research
Disclosure: Nothing to disclose.

CME Editor

Merrily P M Poth, MD, Professor, Department of Pediatrics and Neuroscience, Uniformed Services University of the Health Sciences
Merrily P M Poth, MD is a member of the following medical societies: American Academy of Pediatrics, Endocrine Society, and Lawson-Wilkins Pediatric Endocrine Society
Disclosure: Nothing to disclose.

Chief Editor

Stephen Kemp, MD, PhD, Professor, Department of Pediatrics, Section of Pediatric Endocrinology, University of Arkansas and Arkansas Children's Hospital
Stephen Kemp, MD, PhD is a member of the following medical societies: American Academy of Pediatrics, American Association of Clinical Endocrinologists, American Pediatric Society, Endocrine Society, Phi Beta Kappa, Southern Medical Association, and Southern Society for Pediatric Research
Disclosure: Genentech, Inc. Honoraria Speaking and teaching; Pfizer, Inc. Honoraria Consulting

 
 
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