Diabetes Insipidus: Diagnosis and Treatment
Diabetes insipidus is a term for any condition that causes your body to make a lot of urine and make you extra thirsty.This condition is nothing to do with high blood sugar.
Diabetes Insipidus should be diagnosed for the particular type of DI as the treatment is different for all kind. To distinguishing DI from other causes of excessive urination a number of test can be done.
Fluid deprivation test is done to help determine if DI is caused by a defect in ADH production or a defect in the kidneys' response to ADH. In this test fluids are withheld to induce dehydration to measures the changes in body weight, urine output, and urine composition.
In normal body condition, the kidney conserve water by concentrating the urine in case of dehydration. People with DI continue to urinate large amounts of dilute urine in spite of water deprivation.
If the urine osmolality increases and stabilize at above 280 Osm/kg with fluid restriction,this indicates primary polydipsia. A stabilization at a lower level indicates diabetes insipidus.The increase in urine osmolality is less than 30 Osm/kg per hour for at least three hours refer to as Stabilization in this test.
Desmopressin can be given as an injection, a nasal spray, or a tablet. This can lead to sudden fluid accumulation in the central nervous system. Thus the patient is advised to drink fluids or water only when thirsty and not at other times while taking desmopressin. If desmopressin reduces urine output and increases urine osmolarity, the hypothalamic production of ADH is deficient, and the kidney responds normally to desmopressin.
Desmopressin does not change either urine output or osmolarity if the DI is due to renal pathology.
Particularly a pituitary MRI, is done to find out if a disease such as a prolactinoma, or histiocytosis, syphilis, tuberculosis or other tumor or granuloma is affecting pituitary function.
A magnetic resonance imaging test as well as testing of other hormones of the pituitary can determine if it is central DI .
Genetic screening is done if you have a family history of polyuria.
Depending on what type of diabetes insipidus you have,the treatment options include:
The cause of central DI is due to lack of anti-diuretic hormone (ADH).Hence the treatment is usually with a synthetic hormone called desmopressin. You can take desmopressin as a nasal spray, as oral tablets or by injection. Desmopressin eliminates the increase in urination. For most people with central DI, desmopressin is safe and effective. It should be considered as a medication you take as and when required.
Taking more desmopressin than required can result in too much water retention and low sodium levels in the blood. Symptoms of low sodium include lethargy, headache, nausea and, in severe cases, seizures. In mild cases of central diabetes insipidus, you may need only to increase your water intake.
Nephrogenic diabetes insipidus causes when your kidneys not properly responding to ADH.The treatment procedures follows a low-salt diet to help reduce the amount of urine your kidneys make. You also need to drink enough water to avoid dehydration. The diuretic hydrochlorothiazide (a thiazide diuretic) or indomethacin can be used to improve nephrogenic diabetes insipidus.
Gestational diabetes insipidus is treated with the synthetic hormone desmopressin. If gestational DI is caused by an abnormality in the thirst mechanism, desmopressin is not advised.
Primary Polydipsia can be treated by decreasing the amount of fluid intake.