Diabetes Insipidus

A rare form of diabetes resulting from a deficiency of vasopressin (the pituitary hormone that regulates the kidneys); characterized by the chronic excretion of large amounts of pale dilute urine which results in dehydration and extreme thirst.

Signs and symptoms

While most people make 1 to 3 quarts of urine a day, people with diabetes insipidus can make up to 20 quarts of urine a day. People with this disorder need to urinate frequently, called polyuria. They may also feel thirsty all the time and drink lots of liquids, a condition called polydipsia.

Symptoms of dehydration may include

• thirst
• dry mouth
• feeling dizzy or light-headed when standing
• feeling tired
• difficulty performing simple mental tasks
• nausea
• fainting
• Seek care right away

Severe dehydration can lead to seizures, permanent brain damage, and even death. Seek care right away if you feel

• confused
• dizzy
• sluggish

Causes

Diabetes insipidus is usually caused by problems with a hormone called vasopressin that helps your kidneys balance the amount of fluid in your body. Problems with a part of your brain that controls thirst can also cause diabetes insipidus. Specific causes vary among the four types of diabetes insipidus: central, nephrogenic, dipsogenic, and gestationa

Central diabetes insipidus

In central diabetes insipidus, your body doesn’t make enough vasopressin, also called “antidiuretic hormone.” Vasopressin is produced in your hypothalamus, a small area of your brain near the pituitary gland. When the amount of fluids in your body falls too low, the pituitary gland releases vasopressin into your bloodstream. The hormone signals your kidneys to conserve fluids by pulling fluids from your urine and returning fluid to your bloodstream. But if your body can’t make enough vasopressin, the fluid may get flushed out in your urine instead.

Causes of central diabetes insipidus include

• damage to your hypothalamus or your pituitary gland from surgery, infection, inflammation, a tumor, or a head injury
• an autoimmune disorder
• an inherited gene mutation
• Nephrogenic diabetes insipidus
• In nephrogenic diabetes insipidus, your body makes enough vasopressin but your kidneys don’t respond to the hormone as they should. As a result, too much fluid gets flushed out in your urine. Causes include
• low levels of potassium in your blood
• high levels of calcium in your blood
• a blocked urinary tract
• an inherited gene mutation
• chronic kidney disease, though rarely
• Dipsogenic diabetes insipidus

In this type of diabetes insipidus, a problem with your hypothalamus causes you to feel thirsty and drink more liquids. As a result, you may need to urinate often. Causes include

• damage to your hypothalamus from surgery, infection, inflammation, a tumor, or a head injury
• some medicines or mental health problems
• Gestational diabetes insipidus
• Gestational diabetes insipidus is a rare, temporary condition that can develop during pregnancy. This type of diabetes insipidus occurs when the mother’s placenta makes too much of an enzyme that breaks down her vasopressin.
• Women who are pregnant with more than one baby are more likely to develop the condition because they have more placental tissue.
• Because the liver plays a role in curbing the enzyme that breaks down vasopressin, diseases and conditions that affect liver function also increase risk. Examples include preeclampsia and HELLP syndrome

Diagnosis

• Urinalysis can show if your urine is too diluted, or watery. It can also show if the level of glucose in your blood is too high, which is caused by diabetes mellitus, not diabetes insipidus.
• Blood tests can measure sodium levels and the amount of certain substances in your blood, which can help diagnose diabetes insipidus and, in some cases, determine the type.
• Water deprivation test. This test can help health care professionals diagnose diabetes insipidus and identify its cause.
• Magnetic resonance imaging (MRI) - An MRI uses magnets and radio waves to make pictures of your brain tissues.
• Stimulation tests. During these tests, you are given an intravenous solution that stimulates your body to produce vasopressin.
• Measuring blood level of copeptin, a substance that increases when vasopressin does, can indicate if you have diabetes insipidus or a different condition called primary polydipsia, which can cause you to drink lots of liquids.

Treatment

The main way to treat diabetes insipidus is to drink enough liquids to prevent dehydration.

Central diabetes insipidus

Ccentral diabetes insipidus with a man-made hormone called desmopressin

Nephrogenic diabetes insipidus

• In some cases, nephrogenic diabetes insipidus may go away after treating its cause.
• Other treatments can include nonsteroidal anti-inflammatory drugs or other types of diuretics.

Dipsogenic diabetes insipidus

• Researchers haven’t found an effective way to treat dipsogenic diabetes insipidus.
• Sucking on ice chips or sugar free candies to moisten your mouth and increase saliva flow may help reduce your thirst.
• A small dose of desmopressin at bedtime can also be prescribed.

Gestational diabetes insipidus

• Gestational diabetes insipidus is treated with desmopressin, which is safe for both mother and baby.
• An expectant mother’s placenta does not destroy desmopressin as it does vasopressin.
• Gestational diabetes insipidus usually goes away after the baby is born, but may return if the mother becomes pregnant again.

Complications

• The main complication of diabetes insipidus is dehydration, which happens when your body loses too much fluid and electrolytes to work properly.
• If you have diabetes insipidus, you can usually make up for the large amount of fluids you pass in your urine by drinking more liquids.
• But if you don’t, you could quickly become dehydrated.

This article is a stub. You can help WikiMD by registering to expand it. Editing is available only to registered and verified users. WikiMD is a comprehensive, free health & wellness encyclopedia.