ArginineVasopressin Deficiency (Central Diabetes Insipidus)

Argininevasopressin deficiency results from a deficiency of vasopressin. The deficiency may be

Other disorders that can cause central diabetes insipidus include

Arginine vasopressin resistance Nephrogenic Diabetes Insipidus In nephrogenic diabetes insipidus, the kidneys produce a large volume of dilute urine because the kidney tubules fail to respond to vasopressin (antidiuretic hormone) and are unable to reabsorb... read more (nephrogenic diabetes insipidus) is another type of diabetes insipidus in which there is an adequate amount of vasopressin, but abnormalities in the kidneys cause them not to respond to vasopressin.

Symptoms may begin gradually or suddenly at any age. Often the only symptoms are

The person urinates excessively and often wakes during the night to urinate. A person may drink huge amounts of fluid—4 to 40 quarts (3 to 30 liters) a day—to compensate for the fluid lost in urine. Ice-cold water is often the preferred drink. When compensation is not possible, dehydration Dehydration Dehydration is a deficiency of water in the body. Vomiting, diarrhea, excessive sweating, burns, kidney failure, and use of diuretics may cause dehydration. People feel thirsty, and as dehydration... read more can quickly follow, resulting in low blood pressure and shock. The person continues to urinate large quantities of dilute urine, and this excessive urination is particularly noticeable during the night.

Doctors suspect argininevasopressin deficiency in people who produce large amounts of urine. They first test the urine for sugar to rule out diabetes mellitus Diabetes Mellitus (DM) Diabetes mellitus is a disorder in which the body does not produce enough or respond normally to insulin, causing blood sugar (glucose) levels to be abnormally high. Symptoms of diabetes may... read more (a more common cause of excessive urination). Blood tests show abnormal levels of many electrolytes, including a high level of sodium.

The water deprivation test is the best test to diagnose argininevasopressin deficiency. In a water deprivation test, urine production, blood electrolyte levels, and weight are measured regularly for a period of about 12 hours, during which the person is not allowed to drink. A doctor monitors the person's condition throughout the course of the test. At the end of the 12 hours—or sooner if the person has a decrease in blood pressure, an increase in heart rate, or a loss of more than 5% of body weight—the doctor stops the test and injects vasopressin. The diagnosis of argininevasopressin deficiency is confirmed if, in response to vasopressin, the person's excessive urination stops, the urine becomes more concentrated, the blood pressure rises, and the heart beats more normally. The diagnosis of nephrogenic diabetes insipidus is made if, after the injection, the excessive urination continues, the urine remains dilute, and blood pressure and heart rate do not change.

Doctors sometimes measure the level of circulating vasopressin or copeptin (a piece of the vasopressin hormone) in the blood to confirm argininevasopressin deficiency. However, vasopressin and copeptin levels are difficult to measure, and the tests are not routinely available. Copeptin and vasopressin levels determined without water deprivation are generally not helpful in diagnosis. Additionally, the water deprivation is so accurate that direct measurement of vasopressin or copeptin is usually unnecessary.

Desmopressin (a longer acting form of vasopressin) may be taken as a nasal spray twice a day or sometimes as a tablet or as an injection under the skin or into a vein (intravenously). The dose is adjusted to maintain the body's water balance and a normal urine output. Taking too much vasopressin can lead to fluid retention, swelling, and other problems. People with central diabetes insipidus who are undergoing surgery or are unconscious are generally given injections of vasopressin.

Sometimes argininevasopressin deficiency can be controlled with medications that stimulate production of vasopressin, such as chlorpropamide, carbamazepine, clofibrate, and thiazide diuretics. These medications are unlikely to relieve symptoms completely in people whose argininevasopressin deficiency is severe.