Diabetes Insipidus

Diabetes Insipidus vs. Diabetes Mellitus
Diabetes insipidus is often mistaken for diabetes mellitus, also known as sugar diabetes (type 1 and type 2). Surprisingly, the two conditions are unrelated in cause. Diabetes mellitus is caused by a deficiency of or resistance to insulin, resulting in high blood sugar. Diabetes insipidus, on the other hand, is caused by a deficiency of or resistance to vasopressin, a natural hormone that suppresses urine production. But both conditions share similar signs and symptoms—specifically, excessive thirst and excessive urination.
Symptoms – Excessive Thirst & Excessive Urination
The symptoms of diabetes insipidus cause a frustrating cycle—your body produces excess amounts of dilute urine, draining you of water and causing you to feel thirsty. So you drink a lot, but then you have to urinate even more frequently. This cycle can cause a lack of sleep and in some cases bedwetting. It may also lead to dehydration, confusion, irritability, vomiting, diarrhea, and/or a loss of consciousness. Fortunately, diabetes insipidus is rarely life threatening and in most cases can be treated. Treatment options depend on which of the four forms of diabetes insipidus you have. They are Neurogenic DI, Nephrogenic DI, Gestagenic DI, and Dipsogenic DI.
Neurogenic DI
Also known as central diabetes insipidus, this form is caused by a deficiency of the antidiuretic hormone vasopressin. Sometimes this is caused by damage to the pituitary gland where the hormone is produced. Other times the cause is unknown.To fight against vasopressin deficiency, a doctor may prescribe desmopressin—a synthetic replacement that decreases the body’s urine production.
Nephrogenic DI
This form of diabetes insipidus is caused not by a deficiency of vasopressin, but by insensitivity to the hormone. In such cases, desmopressin won’t help. Instead, nephrogenic DI can be managed through a low-sodium (and occasionally low protein) diet and/or medications such as hydrochlorothiazide and amiloride. Consult your doctor before taking such medications as they may deplete your body’s potassium levels, causing potentially dangerous side effects.
Gestagenic DI
Like neurogenic DI, this form is also caused by a deficiency of vasopressin. But unlike neurogenic DI, gestagenic diabetes insipidus only occurs during pregnancy. Why? An enzyme created by the placenta destroys the mother’s vasopressin levels. In many cases gestagenic DI can be treated with desmopressin, but there are exceptions so talk to your doctor first.
Dipsogenic DI
Dipsogenic DI is a type of primary polydipsia and perhaps the scariest form of diabetes insipidus. It’s caused by a defect or damage in the part of your brain that controls thirst. Your thirst increases so you start drinking more. Then, the extra fluid intake suppresses vasopressin secretion, so you start urinating more. The worst thing about dipsogenic DI is that scientists have yet to find an effective treatment. Patients can decrease their fluid intake, but they’ll still feel thirsty. Desmopressin should not be used to treat dipsogenic DI as the combination of decreased urine output and increased fluid intake can result in water intoxication, a condition that may cause serious brain damage.

Diabetes Insipidus:

“The Other Diabetes”

Diabetes insipidus, also known as “water diabetes” is a rare, not widely diagnosed disease in which the kidneys produce abnormally large amounts of dilute urine. The name is derived from—

Diabainein (Greek): “to pass through”
Insipidus (Latin): “having no flavor”

Although diabetes insipidus is rare, those who live with it are certainly not alone. Current estimates are that about 3 in 100,000 have it, which comes to well over 3,000 in the United States. If you think you have diabetes insipidus, remember that most forms can be treated. Talk to your doctor to determine what form you have, and what you can do to move forward.