Diabetes InsipidusDiabetes insipidus (DI) is a form of diabetes which is much different from diabetes mellitus. One type of diabetes is known as “water” diabetes and the other “sugar” diabetes. Water diabetes has nothing to do with the production and use of insulin by the body. The production of insulin by the islets of the pancreas and the use of insulin by the cells and muscle tissues only relates to diabetes mellitus. How does DI works?Over sixty percent of the body is made up of water. This water balance in the body is regulated by a hormone knows as the anti-diuretic hormone (ADH) or vasopressin. This hormone is made in a part of the brain called the hypothalamus and is stored in the pituitary gland for later use as required. If the water level in the body becomes too low the ADH is released from the pituitary gland. It tells the kidneys to not extract water from the body. In other words it stops the kidneys from producing urine. The problem with DI is that the ADH does not stop the kidneys from producing urine. This malfunction allows too much fluid to pass from the body. Why the confusion with diabetes mellitus?The main confusion is that in both types of diabetes the main symptoms are very similar. They are excess thirst (polydipsia), and urinating frequently (polyuria) and in large quantities. The sensation of thirst stimulates patients to drink large amounts of water to compensate for water lost in the urine. Types of DIThere are two main types of DI. They are namely: • Central diabetes insipidus - is caused by damage to the hypothalamus where ADH is produced or pituitary gland where ADH is stored. These damages could be as a result of surgery, infection, tumor, or head injury. • Nephrogenic diabetes insipidus(NDI) - involves a defect in the parts of the kidneys that reabsorb water back into the bloodstream. NDI may occur as an inherited disorder or may be as a result of amyloidosis, polycystic kidney disease. and the effects of certain drugs (for example, lithium)
|
