Find out what diabetes insipidus is, what can cause this rare condition and what the impact may be on your child's future.
Key points
Diabetes insipidus is different than diabetes associated with high blood sugar (diabetes mellitus).
Diabetes insipidus reflects the body’s inability to retain water and results in large amounts of dilute urine.
Diabetes insipidus may be caused by a brain tumour or by the surgery to treat it.
Diabetes insipidus is usually treated with a synthetic form of antidiuretic hormone called desmopressin (DDAVP).
If the condition is not treated it can lead to dehydration and an electrolyte imbalance.
In some cases, diabetes insipidus may go away a few weeks after surgery, but often it is permanent.
Introduction
What is diabetes insipidus
Water retentionThe hypothalamus and pituitary gland produce hormones that are involved in controlling thirst and the need to urinate. These hormones trigger the kidneys to conserve water.
Diabetes insipidus (DI) is a condition that reflects the body’s inability to retain water. As a result, if not treated, large amounts of dilute (colourless) urine are produced, leading to the need to urinate (pee) frequently. It may also cause intense feelings of thirst. DI is rare. It may happen when the
brain tumour is near the
hypothalamus or pituitary gland, or if there is damage to these areas during surgery.
The hypothalamus is our "thirst centre," and senses when we need to drink. This helps ensure our body has enough water and does not become dehydrated. The hypothalamus produces a hormone called antidiuretic hormone (ADH), which is also called vasopressin. ADH helps the body retain water. It is stored and released from the pituitary gland. It then acts on kidneys. The kidneys concentrate our urine to help conserve water. Without ADH, DI develops, and the kidneys cannot retain water and the urine becomes dilute or watery. This causes children with DI to pee a large amount and may cause them to be extremely thirsty to encourage them to replace the water that was lost in the urine. If your child does not act on the feeling of thirst and drink enough fluids, they may become dehydrated.
Some children with brain tumours lose their sense of thirst and may need to carefully monitor fluid intake and output to remain healthy.
Causes, risk factors and prevalence
What causes diabetes insipidus?
There are two possible causes of diabetes insipidus:
The tumour: If a tumour is pressing on the hypothalamus or pituitary gland, it may affect the production of antidiuretic hormone (ADH).
The surgery: The pituitary stalk may be cut or damaged during removal of the tumour. This affects the production of ADH for a few weeks, or in some cases permanently.
Diagnosis
How do we screen for diabetes insipidus?
The health-care team will monitor the amount of urine production. If there is concern for DI, urine tests will be done to check concentration and water balance in the body, particularly during and after surgery.
Treatment
How can diabetes insipidus be treated?
DI related to brain tumours can be treated with a synthetic form of ADH (also called desmopressin or DDAVP). It is typically taken as a pill or as a tablet that melts beneath the tongue to replace the ADH produced by the pituitary gland.
Follow-up care
How will this affect your child’s future?
Children who have DI may need to take desmopressin supplements for life. They should always have access to water and be allowed to drink if they are thirsty. If your child is required to restrict their fluid intake or if they are unwell and cannot drink, the health-care team should be contacted to determine how to prevent dehydration. This may involve administering fluids intravenously (through an IV). If the condition is not treated, it can lead to dehydration or an imbalance of electrolytes.
