3. LEARNING OUTCOMES
By the end of this presentation one will be able to:
define Diabetes insipidus (DI)
explain in detail the pathophysiology of DI
discuss the clinical manifestations of DI
explain clinical, laboratory and imaging diagnosis of DI
discuss the treatment for DI
explain the complications due to DI.
4. NORMAL REGULATION OF BODY
WATER
• Normally, low blood volume and high serum osmolarity
stimulates the hypothalamus to produce ADH which goes to
the posterior pituitary gland and is then released into the
blood stream. ADH reaches the nephrons of the kidney via
the bloodstream. Here, it acts on a specific part of the
nephron known as the collecting duct. In the collecting duct
are Aquaporin II channels which reabsorb water. ADH
stimulates production of more AQ2 channels, causing more
water reabsorption.
6. DIABETES INSIPIDUS
The disorder caused by hyposecretion or inadequate action of
Antidiuretic Hormone (ADH) or Vasopressin.
NB: ADH regulate the amount of body fluids(water).
In Diabetes Insipidus, there is decreased action of ADH, causing decrease
in aquaporin-II channels in collecting tubule and decreased water
reabsorption.
There are two main types of DI
1. Central Diabetes Insipidus
7. cont.
Cranial/ central DI is a common type of DI which
occurs when the body does not produce enough
ADH.
Nephrogenic DI: this is a type of DI where ADH is
produced at the right levels but kidneys do not
respond to the hormone (kidneys are resistant to the
ADH).
Other types of DI: gestational DI and dipsogenic DI
8. CAUSES OF DI
Central DI CAUSED BY:
• A brain tumor that damages hypothalamus
or pituitary gland.
• severe head injury that damages the
hypothalamus or pituitary.
9. cont.
• complications that occur during brain or pituitary
surgery.
• cancers that spread from another part of the body
to the brain.
• brain damage caused by a hypoxia, which can occur
during stroke or drowning.
10. cont.
Nephrogenic DI:
• Mutation of the aquaporin receptors.
• chronic kidney diseases such as
glomerulonephritis may also alter the response
of the kidney to ADH.
12. CLINICAL MANIFESTATION
• polyuria
the decreased action of ADH, leads to decreased collecting
tubule water reabsorption, leading to more urine production,
thereby resulting into frequent urination.
• polydipsia
Without ADH, the kidneys do not reabsorb water properly
leading to excessive water loss in large amounts of urine which
results in thirst increasing due to the body trying to balance the
water loss.
13. Cont.
• postural Hypotension
low level of ADH causes the failure of water
reabsorption. urine volume will increase
leading to dehydration and fall in blood
pressure.
14. • enuresis
decrease action of ADH, often intense with the
need to drink large amount of water, excessive
urine production, with the need to urinate
frequently(polyurea) often every hour,
throughout a day and night,thereby leading to
new onset of bedwetting.
15. Cont:
• hypovolemia
When there is low or no ADH released ,there
is no reabsorption which results in excessive
loss of water leading to dehydration.
16. cont.
• weight loss
low level of ADH leads to polydipsia which interferes with nutritional
intake
• Dehydration
Loss of water in Urine due to inadequate action of
ADH.
• Electrolytes imbalance
Low ADH result into failure of water reabsorption
leading to high electrolyte level in the body.
17. DIAGNOSIS
CLINICAL:
• Water deprivation test- involves not any liquid for several
hours to see how body respond .
LABORATORY
• Urinalysis: is the analysis of urine content
• decreased urine osmolality
19. cont.
IMAGING
• MRI scan: a scan that uses a strong magnetic
field and radio waves to produce images of the
brain.
• CT scan: a procedure that uses a computer
linked to an x-ray machine to make a series of
detailed pictures of brain.
20. TREATMENT
• Underlay cause management e.g. if DI is caused by
certain kidney diseases, the treatment must firstly
target the kidney disease.
• ADH replacement (desmopressin intake)
• symptoms management e.g. management of
hypotension, hypovolemia, weight loss.
• rehydration IV fluids (hypotonic)
21. COMPLICATIONS
• Chronic Dehydration:
A severe lack of water in the body caused by
Diabetes Insipidus due to failure of water
reabsorption.
Dehydration in DI can lead to:
- dizziness or lightheadedness
- headache
- dry mouth and lips
- sunken features (particularly the eyes)
- confusion and irritability
22. COMPLICATIONS
• Electrolytes imbalance
a condition of high minerals or electrolytes
concentration in the body fluids due to loss amount
of water they were contained in.
Which can in turn leads to
- Weakness
- Vomiting
- Loss of appetite
- muscles cramps
- Confusion
23. REFERENCES
Mayo clinic (2023) Diabetes Insipidus [online]. Available at:
https://www.mayoclinic.org/diseases-conditions/diabetes-
insipidus/symptoms-causes/syc-20351269 (Accessed 26 February 2023.
NHS (2023) Diabetes Insipidus [online]. Available at:
https://www.nhs.uk/conditions/diabetes-insipidus/ (Accessed 26 February
2023).
Sqadia (2023) Diabetes Insipidus [online].Available at:
https://www.sqadia.com/programs/diabetes-insipidus (Accessed 27 February
2023).
Gylyls, B. B, & Wedding, M, A. (2017) Medical Terminology System', "A Body
System Approach", F. A Davis Company, Philadelphia.
