Diabetes Insipidus, rare disease caused by deficiency of vasopressin, one of the hormones of the posterior pituitary gland, which controls the amount of urine secreted by the kidneys. The symptoms of diabetes insipidus are marked thirst and the excretion of large quantities of urine, as much as 4 to 10 liters a day. This urine has a low specific gravity and contains no excess sugar. In many cases, injection or nasal inhalation of vasopressin controls the symptoms of the disease.
Nephrogenic diabetes insipidus (DI) refers to a decrease in urinary concentrating ability that results from resistance to the action of antidiuretic hormone (ADH). This problem can reflect resistance at the ADH site of action in the collecting tubules, or interference with the countercurrent mechanism due, for example, to medullary injury or to decreased sodium chloride reabsorption in the medullary aspect of the thick ascending limb of the loop of Henle. The most common causes of ADH resistance severe enough to produce polyuria are hereditary nephrogenic DI (children) and chronic lithium ingestion, hypokalemia and hypercalcemia (adults).
Central diabetes insipidus (DI) is characterized by decreased release of antidiuretic hormone (ADH), resulting in a variable degree of polyuria. Lack of ADH can be caused by disorders that act at one or more of the sites involved in ADH secretion: the hypothalamic osmoreceptors; the supraoptic or paraventricular nuclei; or the superior portion of the supraopticohypophyseal tract. The most common causes of central DI (CDI), accounting for the vast majority of cases, are neurosurgery or trauma, primary or secondary tumors or infiltrative diseases (such as Langerhans cell histiocytosis), and idiopathic DI.
Central DI — Central DI (also called neurohypophyseal or neurogenic DI) is associated with deficient secretion of antidiuretic hormone (ADH). This condition is most often idiopathic (possibly due to autoimmune injury to the ADH-producing cells), or can be induced by trauma, pituitary surgery, or hypoxic or ischemic encephalopathy. Rare familial cases have been described. (See "Causes of central diabetes insipidus").
Nephrogenic DI — Nephrogenic DI is characterized by normal ADH secretion but varying degrees of renal resistance to its water-retaining effect. This problem, in its mild form, is relatively common, since most patients who are elderly or who have underlying renal disease have a reduction in maximum concentrating ability. This defect, however, is not severe enough to produce a symptomatic increase in urine output.
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