DIABETES MELLITUS

DEFINITION

Diabetes mellitus (pronounced DI-uh-BEE-teez MEH-luh-tuss) is a condition in which the body's cells are no longer able to utilize blood sugar. Blood sugar is the fuel that cells use to make energy. Symptoms of diabetes mellitus include excessive thirst and hunger, frequent urination, and tiredness.

DESCRIPTION

Diabetes mellitus is a chronic health disorder. Chronic means that the condition lasts for many years. Diabetes can cause serious health problems. These problems include kidney failure, heart disease, stroke (see stroke entry), and blindness. About fourteen million Americans have diabetes. As many as half of these people do not know they have the condition.

The Energy Your Body Needs

Our bodies require a constant production of energy. We use that energy to walk, talk, think, and carry on many other activities. The energy comes from the food we eat.

Certain foods contain chemicals known as carbohydrates. When carbohydrates enter the body, they break down to form a simple sugar known as glucose. The glucose travels to cells throughout the body by way of the bloodstream.

To enter a cell, glucose may need the help of another chemical known as insulin. Insulin is produced in the pancreas. Insulin also travels through the bloodstream to all cells in the body. It acts like a key that opens cells so that glucose can enter.

In a healthy body, enough insulin is produced to make sure that all cells get the glucose they need. The cells can then produce enough energy to satisfy the body's needs.

In some cases, however, this system breaks down. One problem may be that the pancreas stops producing enough insulin. There is not enough insulin for all the cells that need it. Glucose cannot get into many of the body's cells. The cells cannot produce enough energy for the body's needs.

Another problem is that some cells may no longer recognize insulin. The pancreas may still produce insulin for all the body's cells, but some cells don't respond to it. Again, glucose can't get into the cells and energy is not produced to satisfy the body's needs.

Types of Diabetes Mellitus

Two types of diabetes mellitus are recognized. These two types differ in two major ways—the age at which they occur and their causes. Type I diabetes is also called juvenile diabetes. It usually begins during childhood or adolescence. In this form of diabetes, the pancreas produces little or no insulin. The condition can be treated by having a person take daily injections of insulin. For this reason, Type I diabetes is also called insulin-dependent diabetes. Type I diabetes affects about three people in one thousand in the United States.

Type II diabetes is sometimes called adult-onset diabetes. The name "adult-onset" comes from the fact that Type II diabetes usually does not appear until a person grows older. More than 90 percent of the diabetics in the United States are Type II diabetics. This form of the disorder is not caused by low levels of insulin. Instead, the body's cells do not recognize insulin in the bloodstream. They are not able to get the glucose they need to make energy.

People with Type II diabetes do not need to take insulin. Their body produces all the insulin it needs. The body just can't use it properly. As a result, Type II diabetes is sometimes called noninsulin-dependent diabetes. Type II diabetes is treated with diet, exercise, and drugs.

CAUSES

The causes of diabetes mellitus are unclear. Both heredity and environment may be involved. Studies have shown that certain genetic factors may be responsible for diabetes. Genes are chemical units found in all cells, that tell cells what functions they should perform. Genes are passed down from parents to children. If parents carry a gene for diabetes, they may pass that gene on to their children.

Some researchers believe that Type I diabetes may also be caused by a virus or some other disease-causing organism. They think the organism may attack the pancreas at an early age. The pancreas may be damaged and lose its ability to produce insulin.

Kaitlyn Bubb, age 7, watches her friend Ivan Kotunov, age 13, perform a blood sugar test. Both children have diabetes. (Reproduced by permission of

AP/Wide World Photos

)

A number of factors have been tied to Type II diabetes. These factors include:

• Obesity (being excessively overweight, see obesity entry)
• Having relatives with diabetes mellitus
• Belonging to certain high-risk populations, such as African Americans, Native Americans, Hispanics, or Native Hawaiians
• Having high blood pressure (see hypertension entry)
• Having an excess or deficiency of certain substances in the blood, such as cholesterol or triglycerides (a form of fat)

SYMPTOMS

The classic symptoms of diabetes include being overly tired and sick, having to urinate frequently, feeling very thirsty and hungry, and losing weight. The way these symptoms develop differs for Type I and Type II diabetes. In Type I diabetes, they usually show up slowly in children or adolescents over a period of a few days or weeks. In Type II diabetes, they develop even more slowly, over a period of years, in adults over the age of forty. Adults often do not realize they have diabetes mellitus. The condition may be discovered only during a routine physical examination for some other problem.

Type I diabetes is generally a more serious condition than Type II. The most dangerous effect of Type I diabetes is a condition known as ketoacidosis (pronounced KEE-toe-ASS-ih-doe-sus), which occurs when Type I diabetes is not controlled. In ketoacidosis, chemicals that are toxic (poisonous) to the body begin to collect in the blood. These chemicals can cause abdominal pain, vomiting, rapid breathing, extreme tiredness, and drowsiness. If this condition is not treated, a person may fall into a coma and die. The most characteristic symptom of ketoacidosis is sweet-smelling breath.

The symptoms of Type II diabetes usually develop more slowly and are less serious. In the worst circumstance, they include heart disease, infections of the gums and urinary tract, blurred vision, numbness in the feet and legs, and slow-healing wounds.

DIAGNOSIS

A patient with the symptoms listed above may be suspected of having diabetes. The diagnosis can be confirmed very easily and quickly with a blood and/or urine test. The amount of glucose present in the blood or urine can be measured. If the level is unusually high, it is likely the person has diabetes.

The simplest test for diabetes uses paper strips that change color when dipped into urine. The color of the strip is compared to a chart that comes with the strips. The chart shows how much glucose is present in the urine.

Blood tests can also be used to test for glucose. These tests tend to be more accurate than urine tests. A sample of blood is taken from the patient's arm. The sample is then analyzed in a laboratory. The amount of glucose present is determined. That amount is compared with the amount present in a healthy person's blood. A high level of glucose suggests the presence of diabetes.

People with diabetes often test their own blood many times a day. They use home glucose test kits that contain a small needle and a chart. They use the needle to produce a single drop of blood (often from their fingertip). The drop is then placed on a spot on the chart that contains a chemical that reacts with glucose. The color produced on the spot can be compared to the chart. It shows the level of glucose in the blood.

TREATMENT

There is currently no cure for diabetes. However, the condition can be managed well enough to allow most people to live normal lives. Treatment of diabetes focuses on two goals. The first is to keep blood glucose within a normal range, and the second is to prevent complications from developing over time.

Lifestyle Changes for Treatment of Type II Diabetes

Obesity is one of the major causes of Type II diabetes. Therefore, controlling one's weight is an important step in controlling the disorder. Type II diabetics are advised to have a well-balanced, nutritious diet and to follow a program of moderate exercise.

The goal in diet planning is to limit one's intake of calories. The term calories is used to describe the energy content of foods. If one takes in too many calories, they are not used to produce energy. They are converted into fat, which is stored in the body. The number of calories a person should take in each day depends on a number of factors, such as age, weight, and level of activity. Many professional organizations have developed diet plans for people with Type II diabetes. These plans insure that people get all necessary nourishment. They also insure that people do not eat more calories than needed for daily activities.

Oral Medications for Type II Diabetes

A number of drugs have been developed for the treatment of Type II diabetes. Most of these drugs belong to a class of compounds known as the sulfonylureas (pronounced SULL-fuh-nil-u-ree-uhz). They include tolbutamide (pronounced toll-BU-tuh-mide), tolazamide (pronounced toll-AZ-uhmide), acetohexamide (pronounced ASS-etto-HECK-suh-mide), and chlorpropamide (pronounced klor-PRO-puh-mide). These drugs stimulate the pancreas to make more insulin.

These drugs all have side effects. For example, they may cause a person to gain weight. But weight gain is often the original cause of the problem for Type II diabetics. So the drugs may not be very useful. They are still not as satisfactory as a well-planned diet and program of exercise. The drugs are also not effective against Type I diabetes.

Insulin: Treatment for Type I Diabetes

Type I diabetes can be treated with daily injections of insulin. The injections provide the insulin that the patient's pancreas doesn't make. The amount of insulin taken depends on many factors, including the patient's age, height, weight, food intake, and level of activity.

In most patients, Type I diabetes can be controlled with insulin injections. (© 1992

Science Photo Library

. Reproduced by permission of

Custom Medical Stock Photo

.)

Insulin injections may also be needed by people with Type II diabetes. The injections are recommended when other methods of controlling the disorder do not work. The injections are given just under the skin anywhere on the body where there is loose skin.

Patients who require multiple insulin shots over the course of the day may be able to use an insulin pump. An insulin pump is a small device worn outside the body. Insulin flows from the pump through a tube connected to a needle. The needle is inserted into the abdomen. The pump is operated by a small battery. The pump can be programmed to inject a certain dose of insulin at given times of the day.

People who take insulin have to plan their injections carefully. Injections should be given to coincide with meals. If they are given at the wrong time, an insulin reaction may occur. An insulin reaction is the result of having too much insulin in the blood. A person may not have had enough to eat, or may have taken too much insulin. The patient may become cranky, confused, tired, sweaty, and shaky. Left untreated, he or she may become unconscious or have a seizure. Treatment for an insulin reaction is to give the patient food that has sugar in it. The sugar helps overcome the excess insulin in the blood.

Treatment of Last Resort: Surgery

In extreme cases, a pancreas transplant may be performed. In this procedure, the patient's own pancreas is removed and a healthy pancreas substituted. If the surgery is successful, the healthy pancreas begins producing insulin in the patient's body.

Surgery is often a treatment of last resort. Any surgical procedure has many risks involved. A doctor wants to be certain that those risks are worth the benefit the patient will gain by having a new pancreas.

Alternative Treatment

Diabetes can usually be treated successfully by the methods described above. A person should use caution in considering alternative treatments. If they are not successful, life-threatening complications can develop.

Some practitioners recommend a variety of herbal treatments for diabetes. Some of these herbs are thought to reduce glucose in the blood. They include fenugreek, bilberry, garlic, and onions. Cayenne pepper has been suggested to relieve pain in some forms of diabetes and ginkgo to prevent eye disorders related to diabetes.

Any therapy that lowers stress levels may be useful in treating diabetes. Such therapies include hypnosis, biofeedback, and meditation.

PROGNOSIS

In most patients, diabetes can be controlled by diet, exercise, and insulin injections. If the condition is not treated, however, some serious complications may result. For example, uncontrolled diabetes is the leading cause of blindness, kidney disease, and amputations of arms and legs. It also doubles a person's risk for heart disease and increases the risk of stroke. Eye problems also occur more commonly among diabetics than in the general population.

Some other long-term effects of diabetes mellitus include the following:

• Loss of sensitivity in certain nerves, especially in the legs and feet
• Foot ulcers
• Delayed healing of wounds
• Heart and kidney disease

PREVENTION

There is currently no way to prevent Type I diabetes. The risk for Type II diabetes can be reduced, however, by maintaining an ideal weight and exercising regularly.

FOR MORE INFORMATION

Books

American Diabetes Association. Diabetes A to Z: What You Need to Know About Diabetes : Simply Put, 3rd edition. Alexandria, VA: American Diabetes Association, 2000.

Edelwich, Jerry, Archie Brodsky, and Ronald A. Arky. Diabetes: Caring for Your Emotions As Well As Your Health, Revised edition. Reading, MA: Perseus Books, 1998.

Guthrie, Diana W. The Diabetes Sourcebook: Today's Methods and Ways to Give Yourself the Best Care, 3rd edition. Los Angeles: Lowell House, 1997.

Milcohovich, Sue K., and Barbara Dunn-Long. Diabetes Mellitus: A Practical Handbook, 7th Ed edition. Palo Alto, CA: Bull Pub. Co, 1999.

Organizations

American Diabetes Association. 1660 Duke Street, Alexandria, VA 22314. (703) 549–1500. Diabetes Information and Action Line: (800) DIABETES. http://www.diabetes.org.

American Dietetic Association. 430 North Michigan Ave., Chicago, IL 60611. (312) 822–0330. http://www.eatright.org.

Juvenile Diabetes Foundation International. 120 Wall Street, New York, NY 10005–4001. (212) 785–9595; (800) JDF–CURE.

National Diabetes Information Clearinghouse. 1 Information Way, Bethesda, MD 20892–3560. (301) 654–3327.

National Institutes of Health. National Institute of Diabetes, Digestive and Kidney Diseases. 900 Rockville Pike, Bethesda, MD 20892. (301) 496–3583. http://www.niddk.nih.gov.

Web sites

"Ask NOAH About: Diabetes." NOAH: New York Online Access to Health. [Online] http://www.noah.cuny.edu/diabetes.diabetes.html (accessed on October 24, 1999).

Centers for Disease Control and Prevention. Diabetes Home Page. [Online] http://www.cdc.gov/nccdphp/ddt/ddthome.htm (accessed on October 24, 1999).

Other

Insulin-Dependent Diabetes. National Institute of Diabetes and Digestive and Kidney Diseases. National Institute of Health, NIH Publication No. 94-2098.

Noninsulin-Dependent Diabetes. National Institute of Diabetes and Digestive and Kidney Diseases. National Institute of Health, NIH Publication No. 92-241.