A Family Doctor's Tale - DIABETES INSIPUS

DOC I HAVE DIABETES INSIPUS


Diabetes Insipidus is an endocrine disease resulting from the loss of antidiuretic hormone (ADH) also known as vasopressin stored in the pituitary gland in the brain.

It is characterized by the copious flow of dilute urine (hence the term diabetes) and excessive thirst .

The Causes of Diabetes Insipidus are:
The cause of diabetes insipidus is unknown in 45 per cent of cases.

A.When it is caused by the lack of ADH, it is called Central Diabetes Insipus.

This usually results from any condition damaging the the neuro-hypophyseal (pituitary gland) system of the brain

It can occur at any age and affects either sex.

It is unusual in infants but can commence in early childhood.

Possible causes of central diabetes insipus are:
1.head injuries or birth injuries


2.neoplasm of the pititary gland


3.eosinophilic granuloma


4.primary or secondary cancer (particlarly breast cancer)


5.sarcoidosis

6.familial diabetes insipus

B.When it is caused by a failure of the kidneys to respond to the ADH hormone, the condition is known as Nephrogenic Diabetes Insipus

There is a defect in the parts of the kidneys that help to reabsorb water back into the bloodstream.

It may occur as a sex-linked inherited disorder where male children receive the abnormal gene  from their mothers.

Nephrogenic diabetes insipus can also be caused by:

1.drugs such as lithium or amphotericin B

2.hypercalcemia or high blood calcium

 3. Kidney problems such as polycystic kidney disease


The symptoms of Diabetes Insipidus are:
Symptoms:
1.polyuria or frequent passing of urine
a.urine output of 5-10 liters per 24 hours
b.specific gravity of urine 1.001 to 1.005

2.polydipsia or excessive thirst (with craving for cold water)

3.no other evidence of ill health

Diagnosis of Diabetes Insipidus is often based on
1. medical symptoms of polyuria and polydipsia


2.Urinary volume and specific gravity

3.Infusion of vasopressin

4.MRI of brain

The complications of Diabetes Insipidus are:

1. dehydration - fever, tachycardia or fast heart beats, sunken eyes, dry skin or mucosa, low blood pressure


2.electrolyte imbalance - which can affect the heart rhythm, fatigue, muscle aches and irritability of the nervous system


3.death from primary or secondary lesion in the brain

The treatment of Diabetes Insipidus is:

The underlying cause must first be treated.

In the case of Central Diabetes Insipus:

1.vasopressin can be given intravenously  or intranasally or as oral medication with very good effect


In the case of Nephrogenic Diabetes Insipus (hereditary or lithium induced)

1. stopping the use of lithium may restore kidney function

2.thiazide diuretics may lower urine output


3.anti-inflammatory medications such as indomethocin given orally may help

The prognosis of Diabetes Insipidus is:
generally good with replacement therapy and if the underlying cause can be treated