Diabetes insipidus; nephrogenic

Alternative names:

acquired nephrogenic diabetes insipidus; gypsy's curse; nephrogenic diabetes insipidus

Definition:

A disorder characterized by pronounced thirst and the passage of large quantities of dilute urine, caused by a defect of the kidney tubules. See also diabetes insipidus; central.

Causes, incidence, and risk factors:

Antidiuretic hormone (ADH; vasopressin) is a hormone produced in the hypothalamus of the brain. It concentrates the urine by triggering the kidneys to reabsorb water into the blood stream rather than excreting water into the urine.

Nephrogenic diabetes insipidus involves a defect in the kidney tubules (the portion of the kidneys that causes water to be excreted or reabsorbed). The kidney tubules lack the receptor for ADH that transmits the instruction to concentrate the urine to the inside of the cells. Excessive amounts of water are excreted with the urine, producing a large quantity of very dilute urine. There is no response to vasopressin, even though the blood level of this hormone is higher than normal.

If thirst mechanisms are normal and adequate fluids are consumed, there are no significant effects on the fluid and/or electrolyte balance of the body. If inadequate fluids are consumed, the high urine output may cause dehydration and high blood sodium.

Nephrogenic dI is a very rare disorder, affecting about 5 out of 100,000 people. It occurs primarily as a congenital, sex-linked disorder (congenital nephrogenic dI) that usually affects men, although women can pass the gene on to their children.

Nephrogenic diabetes insipidus may also be acquired (developed as a result of another disorder) in some people, especially those who have disorders of the renal medulla (such as amyloidosis), myeloma, malnutrition, analgesic nephropathy, decreased serum potassium levels, increased serum calcium levels, sickle cell anemia, and in women who are or who have recently been pregnant. It may be acquired by people who are taking medications including demeclocycline, lithium, and methicillin.

The primary risk factors include family history of congenital DI, and/or a history of medications or disorders associated with acquired nephrogenic dI.