To distinguish DI from other causes of excess urination, blood glucose levels, bicarbonate levels, and calcium levels need to be tested. Measurement of blood electrolytes can reveal a high sodium level (hypernatremia as dehydration develops). Urinalysis demonstrates a dilute urine with a low specific gravity. Urine osmolarity and electrolyte levels are typically low.
a complex disorder of carbohydrate, fat, and protein metabolism that is primarily a result of a deficiency or complete lack of insulin secretion by the beta cells of the pancreas or resistance to insulin. The disease is often familial but may be acquired, as in Cushing's syndrome, as a result of the administration of excessive glucocorticoid. The various forms of diabetes have been organized into categories developed by the Expert Committee on the Diagnosis and Classification of Diabetes Mellitus of the American Diabetes Association. Type 1 diabetes mellitus in this classification scheme includes patients with diabetes caused by an autoimmune process, dependent on insulin to prevent ketosis. This group was previously called type I, insulin-dependent diabetes mellitus, juvenile-onset diabetes, brittle diabetes, or ketosis-prone diabetes. Patients with type 2 diabetes mellitus are those previously designated as having type II, non-insulin-dependent diabetes mellitus, maturity-onset diabetes, adult-onset diabetes, ketosis-resistant diabetes, or stable diabetes. Those with gestational diabetes mellitus are women in whom glucose intolerance develops during pregnancy. Other types of diabetes are associated with a pancreatic disease, hormonal changes, adverse effects of drugs, or genetic or other anomalies. A fourth subclass, the impaired glucose tolerance group, also called prediabetes, includes persons whose blood glucose levels are abnormal although not sufficiently above the normal range to be diagnosed as having diabetes. Approximately 95% of the 18 million diabetes patients in the United States are classified as type 2, and more than 70% of those patients are obese. About 1.3 million new cases of diabetes mellitus are diagnosed in the United States each year. Contributing factors to the development of diabetes are heredity; obesity; sedentary life-style; high-fat, low-fiber diets; hypertension; and aging. See also impaired glucose tolerance, potential abnormality of glucose tolerance, previous abnormality of glucose tolerance.
Dipsogenic diabetes insipidus. Researchers have not yet found an effective treatment for dipsogenic diabetes insipidus. People can try sucking on ice chips or sour candies to moisten their mouths and increase saliva flow, which may reduce the desire to drink. For a person who wakes multiple times at night to urinate because of dipsogenic diabetes insipidus, taking a small dose of desmopressin at bedtime may help. Initially, the health care provider will monitor the patient’s blood sodium levels to prevent hyponatremia, or low sodium levels in the blood.
When glucose concentration in the blood remains high over time, the kidneys reach a threshold of reabsorption, and the body excretes glucose in the urine (glycosuria). This increases the osmotic pressure of the urine and inhibits reabsorption of water by the kidney, resulting in increased urine production (polyuria) and increased fluid loss. Lost blood volume is replaced osmotically from water in body cells and other body compartments, causing dehydration and increased thirst (polydipsia). In addition, intracellular glucose deficiency stimulates appetite leading to excessive food intake (polyphagia).
At the end of the test, a health care provider will compare the patient's blood sodium, vasopressin levels, and urine concentration to determine whether the patient has diabetes insipidus. Sometimes, the health care provider may administer medications during the test to see if they increase a patient's urine concentration. In other cases, the health care provider may give the patient a concentrated sodium solution intravenously at the end of the test to increase the patient's blood sodium level and determine if he or she has diabetes insipidus.
Two types of diabetes were identified as separate conditions for the first time by the Indian physicians Sushruta and Charaka in 400–500 CE with one type being associated with youth and another type with being overweight. The term "mellitus" or "from honey" was added by the Briton John Rolle in the late 1700s to separate the condition from diabetes insipidus, which is also associated with frequent urination. Effective treatment was not developed until the early part of the 20th century, when Canadians Frederick Banting and Charles Herbert Best isolated and purified insulin in 1921 and 1922. This was followed by the development of the long-acting insulin NPH in the 1940s.
Excessive urination and extreme thirst and increased fluid intake (especially for cold water and sometimes ice or ice water) are typical for DI. The symptoms of excessive urination and extreme thirst are similar to what is seen in untreated diabetes mellitus, with the distinction that the urine does not contain glucose. Blurred vision is a rarity. Signs of dehydration may also appear in some individuals, since the body cannot conserve much (if any) of the water it takes in.
During digestion, pancreatic beta cells release not only insulin, but in a much smaller amount, the hormone amylin, which helps mediate sharp rises in blood glucose levels following meals. Pramlintide (Symlin) is a new, synthetic form of amylin that may help improve blood glucose control for some type 1 and type 2 diabetic people who use insulin. Pramlintide has few side effects (nausea is the main one) but it adds another set of injections to a diabetic person's daily pharmaceutical routine, as it cannot be mixed in the same syringe with insulin.