As nephrogenic diabetes (NDI) insipidus is defined as the inability to concentrate urine. The reason is an impaired renal tubular response to the antidiuretic hormone vasopressin (ADH). This leads to the excretion of large amounts of diluted urine. The nephrogenic diabetes can be hereditary or secondary result from changes that affect the renal concentration. Symptoms include polyuria, dehydration and hypernatremia. Diagnosis is based on measuring the change in urine osmolality after fluid removal and / or administration of exogenous vasopressin. Treatment consists of adequate fluid intake, thiazide diuretics, NSAIDs and a salt and low-protein diet.

As nephrogenic diabetes (NDI) insipidus is defined as the inability to concentrate urine. The reason is an impaired renal tubular response to the antidiuretic hormone vasopressin (ADH). This leads to the excretion of large amounts of diluted urine. The nephrogenic diabetes can be hereditary or secondary result from changes that affect the renal concentration. Symptoms include polyuria, dehydration and hypernatremia. Diagnosis is based on measuring the change in urine osmolality after fluid removal and / or administration of exogenous vasopressin. Treatment consists of adequate fluid intake, thiazide diuretics, NSAIDs and a salt and low-protein diet.

(Central diabetes insipidus) as nephrogenic diabetes (NDI) insipidus refers to the inability to concentrate urine. The reason is an impaired renal tubular response to the antidiuretic hormone vasopressin (ADH). This leads to the excretion of large amounts of diluted urine. The nephrogenic diabetes can be hereditary or secondary result from changes that affect the renal concentration. Symptoms include polyuria, dehydration and hypernatremia. Diagnosis is based on measuring the change in urine osmolality after fluid removal and / or administration of exogenous vasopressin. Treatment consists of adequate fluid intake, thiazide diuretics, NSAIDs and a salt and low-protein diet. NDI is characterized by the inability to concentrate the urine in response to vasopressin. Central diabetes insipidus is characterized by a lack of vasopressin. Both types of diabetes insipidus can be complete or partial. NDI etiology is either inherited or acquired Hereditary NDI The most common hereditary NDI is an X-linked inherited disorder with variable penetrance in heterozygous women relates to arginine vasopressin (AVP) receptor 2 gene. It may be that heterozygous women have no symptoms or polyuria and polydipsia, to varying degrees, or they can be as badly affected as men. In rare cases, NDI is caused by autosomal recessive or autosomal dominant mutations that affect the aquaporin-2 gene, and can Acquired NDI can occur in both men and women auftreten.Erworbener NDI when noise (many of these are tubulointerstitial diseases) or medications destroy the medulla or the distal nephrons and impair the ability to concentrate urine, which makes it appear as if the kidneys not sensitive to vasopressin. These disorders include: Autosomal dominant polycystic kidney disease Nephronophthisis and complex medullary cystic kidney disease Sichelzellnephropathie release of an obstructive periureteral en Fibrosis Medullary sponge kidney pyelonephritis hypercalcemia amyloidosis Sjogren’s syndrome Bardet-Biedl syndrome, certain cancers (eg, myeloma, sarcoma.) Many drugs , particularly lithium, but other (eg. as demeclocycline, amphotericin B, dexamethasone, dopamine, ifosfamide, ofloxacin, orlistat) may chronic hypokalemic nephropathy an acquired NDI may also be idiopathic. A weak form of acquired NDI can occur in elderly or sick people or patients suffering from acute or chronic renal insufficiency. In addition, certain medical conditions can resemble NDI: The placenta can separate during the second half of pregnancy “Vasopressinase” (this syndrome is gestational diabetes insipidus called). After a pituitary surgery, some patients secrete an inactive precursor of ADH instead vasopressin. Characteristic symptoms and complaints is the production of large amounts of dilute urine (3-20 l / day). Patients typically are thirsty, and the serum sodium is almost normal. Patients for whom water is not easily accessible or can not communicate their thirst (z. B. infants, elderly demented patients) develop as a result of extreme dehydration typically hypernatremia. Hypernatremia can cause neurological symptoms, such as neuromuscular excitability, confusion, seizures, or coma. Diagnosis 24-hour urine volume and osmolality serum electrolytes thirst test NDI is suspected in any patient with polyuria. In infants polyuria can be noticed by the caregivers, if not, the first manifestation may be dehydration. Initial tests include 24-hour urine collection (without fluid restriction) for volume and osmolality as well as serum electrolytes. Patients with NDI divorce> 50 ml / kg urine / day from (polyuria). If the urine osmolality is <300 mOsm / kg (water diuresis), a central diabetes insipidus or NDI is likely. In the NDI urine osmolality is typically <200 mOsm / kg despite clinical signs of hypovolemia (usually the urine osmolality in patients with hypovolemia high). If the osmolality> 300 mOsm / kg, diuresis is likely. Glucosuria and other causes diuresis must be excluded. The serum sodium is slightly increased in patients with adequate fluid intake (142-145 mEq / l) but can increase dramatically in patients who do not get enough liquid. Durst test The diagnosis is made by dehydration test, which measures the maximum achievable concentration and response to exogenous vasopressin. During the test, urine volume and osmolality every hour are measured and the serum osmolality every 2 h. After 3-6 hours of water deprivation is the maximum urine osmolality in patients with NDI unusually low (<300 mOsm / kg). The NDI can be distinguished from a central diabetes insipidus (lack of vasopressin) by administration of exogenous vasopressin (5 units of an aqueous solution vasopressin s.c. or 10 mcg desmopressin intranasal) and by measuring the urine osmolality. In patients with central diabetes insipidus (the urine osmolality increases patient 2 hours after administration of exogenous vasopressin by 50-100% (15-45% with partial central diabetes insipidus). With NDI usually have only a minimal increase in urine osmolality (<50 mOsm / kg;. up to 45% with partial NDI) forecast infants with a hereditary NDI can brain damage with permanent reduced intelligence develop if treatment does not begin early physical growth of the children affected Even under treatment is often delayed, probably. because of frequent dehydration. All complications of NDI except ureteral dilatation are preventable with adequate water intake. A therapy usreichend free water absorption salt and low protein diet eliminating the cause Sometimes a thiazide diuretic, an NSAID or amiloride Treatment consists of adequate water supply, a salt-and low-protein diet, the correction of the cause and the elimination of all nephrotoxins. Serious long-term effects are rare if patients can drink as much as they want. If symptoms persist despite these measures, medications can be given to lower urine output. Thiazide diuretics (eg. As hydrochlorothiazide, 25 mg p.o. once or 2 times daily) may paradoxically reduce urine output, by reducing the excretion of water in the vasopressin-sensitive segments of the collecting pipes. NSAIDs (eg. As indomethacin) or amiloride can also help. Conclusion Patients with NDI are due to limited renal tubul√§rern response to vasopressin unable to concentrate the urine. Let large amounts of dilute urine usually are in accordance thirsty and at normal serum sodium levels. In order to minimize preventable neurological sequelae, a hereditary NDI should be considered in infants with polyuria or in affected family members into consideration. 24-h urine volume and osmolality as well as serum electrolytes must be measured. The diagnosis is confirmed with a thirst test. It is important to provide sufficient free water absorption, and a salt-and low-protein diet. Depending on the need for a thiazide diuretic or amiloride is prescribed.

Health Life Media Team

Leave a Reply