Index of Dictionary Terms

D

Dawn Phenomenon

A sudden rise in blood glucose levels in the early morning hours. This condition sometimes occurs in people with insulin-dependent diabetes and (rarely) in people with noninsulin-dependent diabetes. Unlike the Somogyi effect, it is not a result of an insulin reaction. People who have high levels of blood glucose in the mornings before eating may need to monitor their blood glucose during the night. If blood glucose levels are rising, adjustments in evening snacks or insulin dosages may be recommended. See also: Somogyi effect.

Debridement

The removal of infected, hurt, or dead tissue.

Dehydration

Great loss of body water. A very high level of glucose (sugar) in the urine causes loss of a great deal of water, and the person becomes very thirsty.

Delta Cell

A type of cell in the pancreas in areas called the islets of Langerhans. Delta cells make somatostatin, a hormone that is believed to control how the beta cells make and release insulin and how the alpha cells make and release glucagon.

Desensitization

A method to reduce or stop a response such as an allergic reaction to something. For instance, if a person with diabetes has a bad reaction to taking a full dose of beef insulin, the doctor gives the person a very small amount of the insulin at first. Over a period of time, larger doses are given until the person is taking the full dose. This is one way to help the body get used to the full dose and to avoid having the allergic reaction.

Dextrose

A simple sugar found in the blood. It is the body's main source of energy. Also called glucose. See also: Blood glucose.

Diabetes Control and Complications Trial (DCCT)

A 10-year study (1983-1993) funded by the National Institute of Diabetes and Digestive and Kidney Diseases to assess the effects of intensive therapy on the long-term complications of diabetes. The study proved that intensive management of insulin-dependent diabetes prevents or slows the development of eye, kidney, and nerve damage caused by diabetes.

Diabetes Insipidus

A disease of the pituitary gland or kidney, not diabetes mellitus. Diabetes insipidus is often called "water diabetes" to set it apart from "sugar diabetes." The cause and treatment are not the same as for diabetes mellitus. "Water diabetes" has diabetes in its name because most people who have it show most of the same signs as someone with diabetes mellitus-they have to urinate often, get very thirsty and hungry, and feel weak. However, they do not have glucose (sugar) in their urine.

Diabetes Mellitus

A disease that occurs when the body is not able to use sugar as it should. The body needs sugar for growth and energy for daily activities. It gets sugar when it changes food into glucose (a form of sugar). A hormone called insulin is needed for the glucose to be taken up and used by the body. Diabetes occurs when the body cannot make use of the glucose in the blood for energy because either the pancreas is not able to make enough insulin or the insulin that is availabl e is not effective. The beta
cells in areas of the pancreas called the islets of Langerhans usually make insulin.

There are two main types of diabetes mellitus: insulin-dependent (diabetes type 1) and noninsulin-dependent (diabetes type 2). Ininsulin-dependent diabetes (IDDM), the pancreas makes little or no insulin because the insulin-producing beta cells have been destroyed. This type usually appears suddenly and most commonly in younger people under age 30. Treatment consists of daily insulin injections or use of an insulin pump, a planned diet and regular exercise, and daily self-monitoring of blood glucose.
In noninsulin-dependent diabetes (NIDDM), the pancreas makes some insulin, sometimes too much. The insulin, however, is not effective (see Insulin Resistance). NIDDM is controlled by diet and exercise and daily monitoring of glucose levels.

Sometimes oral drugs that lower blood glucose levels or insulin injections are needed. This type of diabetes usually develops
gradually, most often in people over 40 years of age. NIDDM accounts for 90 to 95 percent of diabetes.

The signs of diabetes include having to urinate often, losing weight, getting very thirsty, and being hungry all the time. Other signs are blurred vision, itching, and slow healing of sores. People with untreated or undiagnosed diabetes are thirsty and have to urinate often because glucose builds to a high level in the bloodstream and the kidneys are working hard to flush out the extra amount. People with untreated diabetes often get hungry and tired because the body is not able to use food the way it should.

In insulin-dependent diabetes, if the level of insulin is too low for a long period of time, the body begins to break down its stores of fat for energy. This causes the body to release acids (ketones) into the blood. The result is called ketoacidosis, a severe condition that may put a person into a coma if not treated right away.

The causes of diabetes are not known. Scientists think that insulin- dependent diabetes may be more than one disease and may have many causes. They are looking at hereditary (whether or not the person has parents or other family members with the disease) and at factors both inside and outside the body, including viruses.

Noninsulin-dependent diabetes appears to be closely associated with obesity and with the body resisting the action of insulin.

Diabetic Amyotrophy

A disease of the nerves leading to the muscles. This condition affects only one side of the body and occurs most often in older men with mild diabetes. See also: Neuropathy.

Diabetic Angiopathy

See: Angiopathy.

Diabetic Coma

A severe emergency in which a person is not conscious because the blood glucose (sugar) is too low or too high. If the glucose level is too low, the person has hypoglycemia; if the level is too high, the person has hyperglycemia and may develop ketoacidosis. See also: Hyperglycemia; hypoglycemia; diabetic ketoacidosis.

Diabetic Ketoacidosis (DKA)

Severe, out-of-control diabetes (high blood sugar) that needs emergency treatment. DKA happens when blood sugar levels get too high. This may happen because of illness, taking too little insulin, or getting too little exercise. The body starts using stored fat for energy, and ketone bodies (acids) build up in the blood.

Ketoacidosis starts slowly and builds up. The signs include nausea and vomiting, which can lead to loss of water from the body, stomach pain, and deep and rapid breathing. Other signs are a flushed face, dry skin and mouth, a fruity breath odor, a rapid and weak pulse, and low blood pressure. If the person is not given fluserids and insulin right away, ketoacidosis can lead to coma and even death.

Diabetic Myelopathy

Spinal cord damage found in some people with diabetes.

Diabetic Nephropathy

See: Nephropathy

Diabetic Neuropathy

See: Neuropathy

Diabetic Osteopathy

Loss of foot bone as viewed by x-ray; usually temporary. Also called "disappearing bone disease."

Diabetic Retinopathy

A disease of the small blood vessels of the retina of the eye. When retinopathy first starts, the tiny blood vessels in the retina become swollen, and they leak a little fluserid into the center of the retina. The person's sight may be blurred. This condition is called background retinopathy. About 80 percent of people with background retinopathy never have serious vision problems, and the disease never goes beyond this first stage.

However, if retinopathy progresses, the harm to sight can be more serious. Many new, tiny blood vessels grow out and across the eye. This is called neovascularization. The vessels may break and bleed into the clear gel that fills the center of the eye, blocking vision. Scar tissue may also form near the retina, pulling it away from the back of the eye. This stage is called proliferative retinopathy, and it can lead to impaired vision and even blindness. See also: Photocoagulation or vitrectomy for treatments.

Diabetogenic

Causing diabetes; some drugs cause blood glucose (sugar) to rise, resulting in diabetes.

Diabetologist

A doctor who sees and treats people with diabetes mellitus.

Diagnosis

The term used when a doctor finds that a person has a certain medical problem or disease.

Dialysis

A method for removing waste such as urea from the blood when the kidneys can no longer do the job. The two types of dialysis are: hemodialysis and peritoneal dialysis. In hemodialysis, the patient's blood is passed through a tube into a machine that filters out waste products. The cleansed blood is then returned to the body.

In peritoneal dialysis, a special solution is run through a tube into the peritoneum, a thin tissue that lines the cavity of the abdomen. The body's waste products are removed through the tube. There are three types of peritoneal dialysis. Continuous ambulatory peritoneal dialysis (CAPD), the most common type, needs no machine and can be done at home. Continuous cyclic peritoneal dialysis (CCPD) uses a machine and is usually performed at night when the person is sleeping. Intermittent peritoneal dialysis (IPD) uses the same type of machine as CCPD, but is usually done in the hospital because treatment takes longer.
Hemodialysis and peritoneal dialysis may be used to treat people with diabetes who have kidney failure.

Diastolic Blood Pressure

See: Blood pressure.

Diet Plan

See: Meal plan.

Dietitian

An expert in nutrition who helps people with special health needs plan the kinds and amounts of foods to eat. A registered dietitian (R.D.) has special qualifications. The health care team for diabetes should include a dietitian, preferably an R.D.

Dilated Pupil Examination

A necessary part of an examination for diabetic eye disease. Special drops are used to enlarge the pupils, enabling the doctor to view the back of the eye for damage.

Distal Sensory Neuropathy

See: Peripheral neuropathy.

Diuretic

A drug that increases the flow of urine to rid the body of extra fluserid.

DKA See: Diabetic ketoacidosis.

DNA (Deoxyribonucleic Acid)

A chemical substance in plant and animal cells that tells the cells what to do and when to do it. DNA is the information about what each person inherits from his or her parents.

Dupuytren's Contracture

A condition that causes the fingers to curve inward and may also affect the palm. The condition is more common in people with diabetes and may precede diabetes.