Diabetes insipidus is a disorder that occurs as a result of a total or partial deficit of a substance called vasopressin. It also occurs when the body resists the absorption of this component. The most typical symptom of this condition is that it produces polyuria or, in other words, more urine than normal. Below, we’ll go into greater detail regarding the symptoms, diagnosis, and treatment of diabetes insipidus.
There are two types of diabetes insipidus (DI): Central and nephrogenic. In both cases, it can be either primary or secondary. Primary diabetes insipidus is a genetic condition while the secondary form is acquired. Central DI originates in the hypothalamus and is the most common form. Nephrogenic DI, on the other hand, originates in the kidneys.
The main symptoms of diabetes insipidus are, as we’ve mentioned, polyuria, as well as polydipsia, and excessive thirst. Patients that suffer from this disease may have urine levels of between 100 oz. and 8 gallons per day. And, if they fail to replenish this liquid, it can lead to dehydration and/or hypovolemia.
Causes of Diabetes Insipidus
Diabetes insipidus occurs when the body is unable to regulate bodily fluids. Under normal circumstances, there’s a balance between the amount of liquid a person consumes and that which the kidneys excrete. When it comes to diabetes insipidus, the body is unable to maintain this important balance.
The excretion function of the kidneys is determined in great part by the production of an antidiuretic hormone. The production of this hormone–vasopressin (ADH)–takes place in the hypothalamus. Subsequently, the hormone is stored in the hypophysis. If the body starts to dehydrate, it releases this hormone into the bloodstream.
What happens next is that the vasopressin activates the kidney tubules. This, in turn, causes the concentration of urine and also causes the tubules to release a certain amount of water into the bloodstream. The purpose of this action is to prevent the water from being lost in the urine.
In the case of central diabetes insipidus, damage exists in the hypothalamus or hypophysis. This damage limits the production, storage, or liberation of vasopressin. In nephrogenic diabetes insipidus, the malfunction occurs in the kidney tubules. These fail to react to the vasopressin hormone in the way they should.
In general, several tests are necessary in order to diagnosis diabetes insipidus. That’s because the symptoms of this disease are similar to those of many other illnesses. The diagnosis must also determine what type of DI the patient is experiencing, which makes the process even more complex.
Generally, doctors will perform the following basic tests:
- The water deprivation test is the most common test. Here, patients must stop ingesting liquids for a period of time, under the supervision of a doctor. The specialist will then monitor the effects of water deprivation on blood, body weight, urine production, and urine concentration.
- Urine analysis. This study determines urine concentration levels. It determines how much water it contains in relation to other substances the body excretes.
- MRI scan. This type of study produces detailed images of the tissue in the brain. This allows specialists to detect if an anomaly exists in the hypnosis or the surrounding areas.
Treatment of Diabetes Insipidus
The treatment of diabetes insipidus depends on the type of DI that affects a patient. In general, the treatment of central diabetes insipidus involves hormonal repositioning and the proper management of the correctable causes. Improper treatment can lead to permanent kidney damage.
Normally, doctors prescribe the use of desmopressin, which is a synthetic analog of the hormone vasopressin. It has vasoconstrictor and antidiuretic properties which have a long-term effect. Most often, it comes in the form of a nasal solution. However, it can also be injected under the skin. However, this should only take place in emergency situations.
In some cases, the treatment of insipidus can involve non-hormonal pharmaceuticals. In this case, there are three different groups of medications. These are prostaglandin inhibitors, thiazide diuretics, and vasopressin-releasing pharmaceuticals. The combination of these medications tends to produce positive results.
However, the treatment of diabetes insipidus is different when it comes to nephrogenic DI. In this case, it usually involves diet and pharmaceuticals in order to reduce the amount of urine.
Usually, doctors prescribe non-steroid anti-inflammatory drugs (NSAID) and thiazide diuretics. What’s more, specialists recommend a diet that’s low in salt and proteins. And, of course, the treatment of diabetes insipidus, no matter the type, always involves preventing dehydration.