Etiology of Diabetes Insipidus

Etiology is a reference to the cause or a set of causes to a specific condition or disorder. It can also refer to the investigation, attribution, or diagnosis of a specific condition, illness, disease, or disorder.

In the etiology of diabetes insipidus, there are four main causes that are currently known to create the condition and its bothersome signs and symptoms.

1. Central Diabetes Insipidus.

The cause of this form of DI in an adult usually originates from damage that has occurred to the hypothalamus or the pituitary gland. The damage causes ADH production, storage, or release to be disrupted. An illness, injury, inflammation, or tumor are common causes of this disorder. For children, it may also be an inherited genetic disorder.

2. Nephrogenic Diabetes Insipidus.

It is an issue with the kidney tubules that causes this form of DI. The tubules are the structures within the kidney which cause water to be either excreted or reabsorbed. It responds to the ADH that is being produced by the body. With this defect in place, the kidneys are unable to respond as they should. Certain drugs, a chronic kidney disorder, and inherited conditions may be responsible for this condition.

3. Gestational Diabetes Insipidus.

This rare condition only affects women during a pregnancy. It occurs when an enzyme that is made by the placenta destroys ADH within the mother, creating the signs and symptoms of DI.

4. Dipsogenic Diabetes Insipidus.

Also referred to as primary polydipsia, this form of DI can be caused by a mental illness or any other condition which causes an individual to excessively drink water or fluids over time. The excessive fluid intake can then suppress the body’s ADH or damage the kidneys, creating the bothersome signs and symptoms that occur with this disorder.

In some individuals, the cause of diabetes insipidus remains unknown. This is because all of the known testing protocols for a diagnosis can indicate that the individual should not have the signs and symptoms of DI, yet they still do.

For those who have a genetic cause for their diabetes insipidus, the symptoms of this disorder will generally present themselves at birth or soon after. It usually affects men, but women can pass the gene for diabetes insipidus on to their children.

What Happens to the Body When Diabetes Insipidus Is Present?

Diabetes insipidus occurs when the body is unable to regulate how it processes fluids that are consumed. In a healthy individual, fluids that are extra will generally be excreted from the body as urine. The excessive fluid is taken from the bloodstream, stored in the bladder, and then removed through urination.

When it is working as it should, the kidneys allow the body to conserve fluid. This means they will make less urine when fluid levels are decreased in the body, concentrating it instead of pulling out more water.

The level of fluids that the body receives is generally regulated by a thirst mechanism that is located in the hypothalamus. If fluid levels are low, the thirst mechanism is initiated, which restores the fluid balance. A hormone, often referred to as ADH or vasopressin, helps to regulate this mechanism with the kidneys. When more of the hormone is present, the kidneys will stop pulling fluids from the blood stream. When it is not present, then more fluids will be taken from the body.

Depending on the type of diabetes insipidus that an individual has, either the levels of ADH will not be appropriate for the fluid levels that a person has or the kidneys will not properly respond to the hormone levels that are present.

What Is the Outcome for a Diabetes Insipidus Diagnosis?

In most cases, diabetes insipidus can be effectively treated. For some individuals, it can even be reversed, especially if it is being caused by a mental illness or is a drug induced version of this disorder.

For many patients, the goal of treatment is to maintain an electrolyte balance while preventing dehydration. In dipsogenic DI, the goal is to expel the excessive water that is being retained by the body.

Central and gestational diabetes insipidus are often treated with a synthetic hormone, which is called desmopressin. It is available via injection, tablets, or as a nasal spray. By replacing the missing ADH, the kidneys will often begin to respond as they should once again.

Nephrogenic diabetes insipidus is often treated by shifting to a low-salt diet and certain medications that can treat the symptoms being experienced.
Dipsogenic diabetes insipidus does not have an official treatment protocol, but is often addressed by using diuretics to expel water.

The etiology of diabetes insipidus can be quite varied, depending on an individual, their medical history, and recent injuries that may have occurred. By understanding the patient, it becomes possible to understand the cause.