What You Need To Know About Diabetes Insipidus

What is diabetes insipidus?

Diabetes insipidus (DI) is a rare disorder affecting the kidneys. The condition inhibits the body's ability to produce enough antidiuretic hormone (ADH). ADH is responsible for keeping the body's urine production in check.

People with DI tend to feel thirsty a lot. They also pee often and in large amounts. In worst-case scenarios, a person with DI may produce up to 30 liters of urine per day, but this is rare.

While "diabetes insipidus" and "diabetes mellitus" sound similar, they're unrelated. Diabetes mellitus, commonly known as diabetes, is a metabolic disorder characterized by a high blood sugar level. At their core, though, these two conditions share some signs and symptoms, like frequent urination and excessive thirst.

DI is generally not deadly if properly managed. One can live a full and healthy life with DI.

Types of diabetes insipidus

Here is an overview of the four main types of DI.

Central

Central DI is a condition that manifests due to damage to the pituitary gland. This consequently hampers the normal production, storage, and release of adequate amounts of antidiuretic hormones. 

Gestational

Gestational DI typically manifests in pregnant women during the third trimester or at the end of the second trimester. It's an incredibly rare complication that occurs in about two to four of every 100,000 pregnancies.¹ This form of DI occurs when the mother's placenta makes too much of an enzyme that breaks down antidiuretic hormone. Gestational DI eventually disappears after the pregnancy.

Dipsogenic

Dipsogenic DI attacks and damages the mechanism that makes a person feel thirsty. As a result, you may feel the urge to drink more fluids even when your body doesn't necessarily need them. Dipsogenic DI is not related to the antidiuretic hormone and typically manifests due to damage to your hypothalamus from inflammation, infection, surgery, or a head injury. 

Nephrogenic 

In nephrogenic DI, your body makes enough antidiuretic hormone, but your kidneys fail to respond to the hormone as they should. As a result, the amount of water in your urine increases significantly. People with this condition produce too much urine, which causes them to be excessively thirsty. 

Symptoms

With diabetes insipidus symptoms, there are two things you should know. Firstly, symptoms manifest slowly and progressively. However, in some children and pregnant mothers, signs, and symptoms appear abruptly — another reason why regular screening is essential in preventing and treating the disease.

Secondly, most of the symptoms of diabetes insipidus align with the symptoms of other conditions. These include diabetes mellitus, polydipsia, kidney disease, polyuria, and dehydration. As such, it's easy to dismiss it for another more concerning condition.

If you display any of these diabetes insipidus symptoms, visit your doctor to know the true cause.

• Having an unquenchable feeling of thirstiness

• Producing large amounts of urine

• Feeling tired 

• Feeling lightheaded and dizzy while standing

• Preferring cold drinks to hot ones

• Fainting

• Bedwetting

• Waking up frequently through the night to urinate

• Colorless urine instead of pale yellow

• Muscle weaknesses

• Dry mouth

• Nausea

• Constipation

You might suffer from severe dehydration if DI progresses. An emergency room evaluation is necessary. 

Causes

Experts believe the primary cause of diabetes insipidus is a damaged or non-functional ADH. 

The hypothalamus is an area of the brain that produces ADH. After production, ADH moves to the pituitary gland, where it stays put until deployment. The exact location of the pituitary gland is below your brain, just behind the bridge of your nose.

ADH is responsible for regulating the volume and osmolarity of urine by controlling the amount of water in your body. 

In diabetes insipidus, ADH fails to keep your body's water level in check. This inevitably leads to your body producing too much urine than what's considered normal.

However, a failing ADH is not the sole cause of diabetes insipidus. Problems with a part of your brain that controls thirst can also trigger DI. Specific causes vary among the four types of diabetes: central, gestational, dipsogenic, and nephrogenic.

Causes of central DI

• A brain tumor

• Brain injury

• Brain surgery

• Tuberculosis

• Stroke affecting the blood supply to the pituitary gland or hypothalamus 

Causes of gestational DI

• Excessive ADH activity 

• Increased prostaglandin levels during pregnancy

Causes of dipsogenic DI

• Excessive drinking of fluid

• Certain mental problems and medications

Causes of nephrogenic DI

Nephrogenic diabetes insipidus can either be acquired or hereditary. The hereditary form manifests as a result of genetic mutation, and its signs usually appear within the first few months of life. The acquired form can result from one or any of the following medications and chronic diseases:

• Lithium

• Low levels of potassium in the blood (hypokalemia

• Obstruction of the urinary tract

• High levels of calcium in the blood (hypercalcemia)

In extremely rare circumstances, diabetes insipidus may result from an autoimmune disorder that causes the immune system to damage the cells that make ADH.

What are the risk factors for developing diabetes insipidus?

Pituitary disorder is a leading risk factor for the development of diabetes insipidus. But there are other risk factors, including:

• Genetic mutations. You're more likely to develop DI if someone in your family has it.

• Brain surgery. According to research, DI is a common complication of pituitary surgery, occurring acutely in 18–30%² of operations.

• Head injury. When you sustain acute head trauma, it can lead to DI.

• Kidney disease. Kidney failure, kidney anomaly, or kidney stones can gradually lead to fluid and electrolyte imbalance in the body, causing DI over time.

• Pregnancy. Pregnant women with more than one baby are more likely to develop the condition.

What are the complications of diabetes insipidus?

Diabetes insipidus rarely leads to complications. Your DI symptoms will remain mild and manageable if you consume enough fluids. However, losing too much fluid can seriously deteriorate your health, and you might even develop acute dehydration.  

Other than dehydration, you're likely to experience any of the following complications if your condition is left unchecked:

• Low body temperature

• Electrolyte imbalance (which can further lead to issues with blood, not clotting, and muscle cramps)

• Brain damage

• Kidney failure

• Weight loss

• Hypotension (low blood pressure)

• Increased heart rate

• Constant fatigue

How is diabetes insipidus diagnosed?

The diagnosis of diabetes insipidus begins with a review of your family and personal history, followed by a physical exam.

You might need to undergo some tests to diagnose your symptoms and rule out other causes. Possible tests include:

Blood test

This helps to determine the level of electrolyte and glucose in your blood. More importantly, this test lets your doctor know if you have diabetes insipidus or diabetes mellitus, as both may present with excessive thirst and urination.

Urine test

This test examines your urine to reveal the level of water in it. If the water content is high and the salt concentration is low, it could be that you have developed DI.

Water deprivation test

During a medical examination, your doctor may decide to deprive you of any and all fluids for several hours. During this time, your doctor will measure your urine output and weight and monitor changes in your urine and blood. 

Though rarely, you might also be given a man-made version of ADH or other ADH-inducing medicine during the test. This lets your doctor know if your body produces enough ADH and if your kidney can respond to the hormone accordingly.

Magnetic resonance imaging (MRI) 

An MRI leverages radio waves and magnets to help visualize your brain tissues. Your doctor may use this test to rule out brain tumors that typically affect the pituitary gland, a potential cause of DI.

Genetic screening

Your doctor may suggest this test if a family member has frequent and excessive urination problems.

Treatment

The main aim of treatment for all types of diabetes insipidus is to relieve thirst and reduce the amount of urine your body produces.

Depending on your DI type, there are several ways of treating your condition and keeping your symptoms under control.

Central DI

To treat central diabetes insipidus, your doctor may suggest taking desmopressin (DDAVP). This medicine is a synthetic version of ADH and usually comes as injections, tablets, or a nasal spray. You'll typically be required to take desmopressin two to three times a day.

Gestational DI

It's safe for both the mother and the baby to take desmopressin while pregnant. Once the baby is born, gestational DI will most likely go away.

Dipsogenic DI

This form of diabetes insipidus is hard to treat, but it can be managed by sucking on ice chips and sugar-free candies. Sugar naturally deprives your mouth of moisture, and its absence can help boost saliva flow and reduce your thirst.

Nephrogenic DI

For this type of diabetes insipidus, desmopressin might not be an ideal treatment option. Instead, your doctor may recommend treating the underlying cause. If it's caused by a drug, switching it with a different one helps. Your doctor may also recommend thiazides, a class of diuretic medicines that help keep your urine production in check.

Other medications may help ease the symptoms, including amiloride and indomethacin.

If the prescribed treatments fail to work, you may need to be booked for further tests.

When to see a doctor if you are concerned about developing diabetes insipidus

Make sure to see a doctor if you develop serious symptoms such as:

• Excessive urination, i.e., most healthy adults pass urine four to seven times a day within 24 hours

• Extreme thirst

• Dry eyes and a dry mouth

• Confusion and irritability

• Feeling you might faint

• Dizziness or lightheadedness

Children tend to urinate more frequently because they have smaller bladders. However, seek immediate medical attention if your child urinates more than ten times a day.

Is it possible to prevent diabetes insipidus?

Diabetes insipidus is hard, if not impossible, to prevent. However, there are ways to lower your risk (or manage your condition if you're diagnosed with diabetes insipidus).

Undiagnosed diabetes insipidus increases the risk of developing various other more severe conditions. Therefore, it's crucial to be aware of DI and pay attention to any unusual symptoms.

You can reduce your risk by regulating your daily fluid intake and only sticking to the recommended amount. The US National Academies of Sciences, Engineering, and Medicine suggests that about 15.5 cups (3.7 liters) of fluids a day is enough for men. For women, the recommended amount is about 11.5 cups (2.7 liters) of fluids a day.

You can also talk to a dietitian about the suitability of eliminating cookies, cakes, dairy desserts, and other sugary foods from your diet. They may recommend embracing sugar-free foods, including fruits, grains, plant proteins, and legumes.

The lowdown

DI is a rare disease that occurs in very few American adults and children. There is no known cure for the condition, but it's manageable. The best way to avoid diabetes insipidus is to avoid triggers, make the necessary lifestyle adjustments, and develop a good relationship with your healthcare provider.