Nephrogenic diabetes insipidus is a defect in the secretion or action of antidiuretic hormone (ADH) that may be central nephrogenic or hypothalamic. And if inadequate fluids are consumed, this may cause high sodium levels and dehydration in the blood because of the amount of water that lost in the urine.
We can also define nephrogenic diabetes insipidus by disordered regulation of water balance due to impaired urinary concentrating ability or inadequate secretion of ADH. If patient is denied to drink a large amount of water or if thirst mechanisms are impaired, this may lead to severe dehydration.
You need also to know that Both central and nephrogenic diabetes insipidus may be inherited primary, familial and congenital or acquired secondary.
Classified as either central diabetes insipidus due to inadequate secretion of ADH or nephrogenic diabetes insipidus due to resistance to ADH action. Characterized by polyuria and markedly dilute urine, with compensatory excessive thirst and polydipsia.
Although both diabetes shared a name, diabetes mellitus and diabetes insipidus are two entirely separate conditions with a separate pathogenesis. They cause polyuria which called, hence the similarity in name. But whereas diabetes insipidus is a problem with the production of antidiuretic hormone that called, Cranial diabetes insipidus. or renal response to antidiuretic hormone which can be called, nephrogenic diabetes insipidus, diabetes mellitus causes polyuria via osmotic diuresis, due to the high blood sugar leaking into the urine, taking excess water along with it.
Nephrogenic diabetes insipidus Causes:
There are many causes of nephrogenic diabetes inspidus, that we can display is these few sentences:
1- Common causes of Nephrogenic diabetes inspidus:
Nephrogenic diabetes insipidus:
A) Acquired forms are common such as lithium therapy.
B) Inherted diabetes insipidus.
Central Diabetes Insipidus:
Trauma: iatrogenic (cranial surgery, especially hypophysectomy; head injury, especially basal skull fractures); the polyuria is often transient in such cases.
Tumors: lymphoma, metastases (especially lung and breast), pineal tumors, hypothalamic tumors and craniopharyngioma.
Idiopathic: about 30% to 50% of all cases and the majority of cases presenting in primary care.
2- Rare Causes:
A) Nephrogenic diabetes insipidus:
Drugs other than lithium: demeclocycline; methoxyflurane; amphotericin B.
Mixed central and nephrogenic diabetes insipidus:
Condition resolves spontaneously after childbirth.
Treatment with desmopressin is often required.
Caused by placental secretion of an enzyme that metabolizes ADH.
Rare complication of pregnancy marked by clinically significant polyuria in the third trimester.
Inherited diabetes insipidus: X-linked recessive inheritance (males are clinically affected, females are carriers; carriers have impaired urinary concentration on formal testing); very rare.
Polycystic kidney disease.
B) Central diabetes insipidus:
Other tumors: primary pituitary tumors, optic gliomas, teratomas.
Sickle cell disease/trait.
Trauma during birth.
Congenital septo-optic dysplasia.
Wolfram syndrome (an autosomal-recessive disorder that is associated with diabetes insipidus, diabetes mellitus, optic atrophy, and deafness).
Inherited (autosomal-dominant inheritance); very rare.
Sheehan syndrome (postpartum pituitary necrosis).
Vascular: hemorrhage, thrombosis, aneurysm.
Granulomatous infiltrations: sarcoidosis, histiocytosis X.
Infection: meningitis, encephalitis, cerebral abscess.
3- Serious Causes:
All causes which areoften readily identified and are serious, but on the other hand, there are slow-growing tumors that may cause nephrogenic diabetes insipidus and may not be detected for a time.
Associated Disorders: Central diabetes insipidus can rarely be associated with:
Hypopituitarism (alterations in water metabolism associated with adrenal insufficiency may mask symptoms/signs of diabetes insipidus until steroid replacement therapy starts).
Congenital septo-optic dysplasia.
Wolfram syndrome: an autosomal-recessive inherited disorder of diabetes insipidus, diabetes mellitus, optic atrophy, and deafness.
Risk Factors: Drug toxicity, especially due to lithium, is the most common cause of nephrogenic diabetes insipidus in adults.
Nephrogenic diabetes insipidus Symptopms:
Symptomatic diabetes insipidus typically occurs when patients lose either their thirst mechanism or their ability to obtain water. If thirst mechanisms are normal and adequate fluids are consumed, patients are usually able to 'self-treat' by drinking fluids, and there are no significant effects on body fluid or salt balance.
Nephrogenic diabetes insipidus Treatment:
The people who have the nephrogenic diabetes insipidus will need to drink a big amount of water and consume enough fluids to equal the amounts that they lost because of producing urine.
Talking about the treatment, you need firstly to correct and underlying cause like hypercalcemia. And the first way you need to walk in is considering a low-protein and low-salt diet.
We have mentioned before that nephrogenic diabetes insipidus causes the excretion of more water than sodium that called dilute urine, so that Thiazide is used in treatment. This condition results in a high serum osmolarity that all the retained solutes stay in the serum, and this high serum osmolarity stimulates polydipsia in an attempt to dilute the serum back to normal and provide free water for excreting the excess serum solutes.