26 years
I suffer from bedweting,after 17 hours without water and food i made test for: osmolarity urine: 632mosm/kg osmolarity blood is:292 is that mean the reason of bedweting from adh hormones?
Sep 5, 2014
The test you underwent is known as the water deprivation test. It's used to figure out if someone who drinks a lot of water (polydypsia) and passes a lot of dilute urine (>3 L per 24 hrs of urine with osmolality of <300 mOsm/kg) has a condition known as diabetes insipidus (DI). DI can occur due to a defect in the brain (central DI) where the hormone ADH that regulates thirst and urine excretion is deficient; it can also be due to a kidney problem (nephrogenic DI) whereby the kidneys cannot concentrate urine.
In healthy individuals, water deprivation leads to a urinary osmolality that is 2-4 times greater than plasma osmolality.
In central and nephrogenic DI, urinary osmolality will be less than 300 mOsm/kg after water deprivation. After the administration of ADH, the osmolality will rise to more than 750 mOsm/kg in central DI but will not rise at all in nephrogenic DI. If however the case is that of primary or psychogenic polydypsia (a persistent sensation of thirst due to an underlying psychological condition), urinary osmolality would be above 750 mOsm/kg after water deprivation. It is therefore unlikely that you have DI.
A urinary osmolality that is 300-750 mOsm/kg after water deprivation and remains below 750 mOsm/kg after administration of ADH may be seen in partial central DI, partial nephrogenic DI, and primary polydipsia.
In order to discern the true cause, combining plasma ADH assay with water deprivation testing can produce higher accuracy in differentiating the different forms of DI from each other and from primary polydipsia.
Other causes of polydypsia and polyuria that should also be ruled out include diabetes mellitus, and medications side effects.
In healthy individuals, water deprivation leads to a urinary osmolality that is 2-4 times greater than plasma osmolality.
In central and nephrogenic DI, urinary osmolality will be less than 300 mOsm/kg after water deprivation. After the administration of ADH, the osmolality will rise to more than 750 mOsm/kg in central DI but will not rise at all in nephrogenic DI. If however the case is that of primary or psychogenic polydypsia (a persistent sensation of thirst due to an underlying psychological condition), urinary osmolality would be above 750 mOsm/kg after water deprivation. It is therefore unlikely that you have DI.
A urinary osmolality that is 300-750 mOsm/kg after water deprivation and remains below 750 mOsm/kg after administration of ADH may be seen in partial central DI, partial nephrogenic DI, and primary polydipsia.
In order to discern the true cause, combining plasma ADH assay with water deprivation testing can produce higher accuracy in differentiating the different forms of DI from each other and from primary polydipsia.
Other causes of polydypsia and polyuria that should also be ruled out include diabetes mellitus, and medications side effects.
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