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Insulin-Dependent Diabetes

Table of Contents

What Is Diabetes?

Diabetes is a group of conditions in which glucose (sugar) levels are abnormally high. Diabetes occurs when the pancreas stops making enough insulin, which is necessary for the proper metabolism of digested foods.

About 14 million people in the United States have some form of diabetes, although only half are diagnosed. The three main types of diabetes are insulin-dependent, also known as Type I diabetes; noninsulin-dependent, also called Type II diabetes; and gestational diabetes, which occurs during pregnancy.

Insulin-dependent diabetes mellitus (IDDM) most often develops in children and young adults. Sometimes people over age 40 get IDDM, but it usually begins at younger ages. For this reason, IDDM used to be known as "juvenile" diabetes. IDDM is one of the most common chronic disorders in U.S. children. Each year, from 11,000 to 12,000 children are diagnosed with IDDM. Among the more than 7 million people in the United States who are being treated for diabetes, about 5 to 10 percent have IDDM.

Noninsulin-dependent diabetes mellitus (NIDDM) is the most common type of diabetes. It accounts for 90 to 95 percent of diagnosed diabetes and almost all of undiagnosed diabetes. NIDDM usually develops in adults over age 40 and is most common in those who are over-weight. People with NIDDM usually produce some insulin, but the body cells cannot use it efficiently because the cells are resistant to the insulin. By losing weight, exercising, or taking oral medications, most people with NIDDM can overcome this resistance to insulin. However, some people with NIDDM require daily insulin injections.

Gestational diabetes occurs in some women during pregnancy. It usually ends after the baby is born, but women with gestational diabetes may develop NIDDM when they get older. Gestational diabetes results from the body's resistance to the action of insulin. This resistance is caused by hormones the placenta produces during pregnancy. The condition develops about midway through the pregnancy. Gestational diabetes is usually treated with diet. Some women may need insulin. Gestational diabetes cannot be treated with pills that lower blood glucose as these medicines can cause harm to the baby.

This booklet is about insulin-dependent diabetes, or IDDM for short. The word "diabetes" in the text refers to insulin-dependent diabetes unless otherwise noted. This booklet does not replace the advice of a doctor. However, it can help you learn about diabetes and suggest questions to ask a doctor. Local diabetes organizations and clinics that sponsor meetings and educational programs about diabetes can also be helpful. See Other Resources for names of groups that have information about diabetes programs.

What Causes Diabetes?

When we eat, foods containing proteins, fats, and carbohydrates are broken down into simpler, easily absorbed chemicals. One of these is a form of simple sugar called glucose. Glucose circulates in the blood stream where it is available for body cells to use. The body relies on glucose as a source of fuel for important organs such as the brain.

The pancreas, a large gland located behind the stomach, produces the hormone insulin. In people without diabetes, the pancreas makes the correct amount of insulin needed to allow glucose to enter body cells. In people with diabetes, however, not enough insulin is produced. As a result, glucose builds up in blood, overflows into the urine, and passes out of the body unused. Thus, the body loses an important source of fuel-even though the blood contains large amounts of glucose.

Insulin also allows the body to store excess glucose as fat, proteins as muscle protein, and important enzymes that control metabolism. A severe deficiency of insulin causes excess breakdown of stored fats and proteins.

What Are the Causes and Symptoms of IDDM?

Causes of IDDM

In people with insulin-dependent diabetes (IDDM), the pancreas produces too little or no insulin at all. The pancreas is not able to produce insulin because the body's immune system has destroyed the insulin-producing cells.

Scientists do not know why the body's immune system, which allows it to fight disease and other "foreign" substances that may invade the body, attacks and destroys insulin-producing cells. A combination of factors may be involved, including exposure to common viruses or other substances early in life, as well as an inherited risk for IDDM.

Researchers can now test family members of people with IDDM to identify those at increased risk for diabetes. Scientists hope to find a way to prevent the disease through a study called the Diabetes Prevention Trial-Type 1. This study is described in the research section of this e-text.

Early Symptoms of IDDM

The early symptoms of IDDM can be gradual or sudden. They include frequent urination (particularly at night), increased thirst, unexplained weight loss (in spite of increased appetite), and extreme tiredness. These symptoms are caused by the build-up of sugar in the blood and its loss in the urine.

To eliminate sugar in the urine, the kidney "borrows" water from the body. The loss of this extra sugar and water in the urine results in dehydration, which causes increased thirst. In addition to causing high blood glucose, the lack of insulin causes the body to break down stored fats and proteins. As fats are broken down, the body can convert these fats into waste products called ketones. If ketone production is excessive, abnormal amounts of ketones in the blood can spill into the urine. If blood ketone levels rise too high, a life-threatening condition called ketoacidosis can develop, which requires immediate medical attention. Symptoms of ketoacidosis include abdominal pain, vomiting, rapid breathing, extreme tiredness, and drowsiness.

Points to remember

The symptoms of IDDM include:

  • Frequent urination Increased thirst
  • Increased hunger
  • Unexplained weight loss
  • Extreme tiredness.

Michael is 10 years old. During his summer break from school he noticed he was always thirsty. He drank many glasses of water, milk, juice, or soda after playing baseball, while he watched TV, and with meals. As a result, Michael needed to urinate constantly. He also complained of being very hungry all the time. Michael's parents took him to the doctor. After learning of his symptoms and performing appropriate tests, Michael's doctor said he had insulin-dependent diabetes and would need to begin taking insulin injections, monitoring his blood sugar levels, and watching his diet.

How Does a Person Live with Diabetes?

Diabetes requires constant attention and daily care to keep blood sugar levels in balance. Injecting insulin, following a diet, exercising, and testing blood sugar are some of the day-to-day requirements. To feel good and stay healthy, a person with IDDM must follow a daily management routine. For this reason, diabetes is often referred to as a "24-hour" disease. This section provides general guidelines for diabetes management and explains the roles of various health care professionals who can help you manage your diabetes. The treatment recommendations are based on a 10-year study recently completed by the Federal Government called the Diabetes Control and Complications Trial (DCCT).

The Diabetes Control and Complications Trial

Diabetes can affect many parts of the body. Over time, it can damage a person's kidneys, eyes, nerves, and heart. These long-term complications can result in kidney disease, vision loss, nerve damage, heart attack, and other problems. The DCCT proved that lowering blood sugar levels delayed or prevented diabetes complications by 50 to 80 percent.

The DCCT compared two approaches to managing IDDM: intensive and standard treatment. People in the intensive treatment group learned how to adjust their insulin according to food intake and exercise. They injected insulin three to four times a day or used an insulin pump and tested their blood sugar at least four times a day and once a week at 3 a.m. They also followed a diet and exercise plan and met once a month with a health care team composed of a physician, nurse educator, dietitian, and mental health professional.

People in the standard treatment group followed a plan that was not as strict. They took one or two insulin injections a day, tested sugar levels once or twice a day, and met with the doctor or nurse every 3 months.

At the end of the DCCT, volunteers on intensive treatment had lower rates of kidney, eye, and nerve damage than volunteers in the standard treatment group. The study showed that efforts to improve control of blood sugar made a major difference. In fact, the study found that any long-term lowering of blood sugar levels will reduce the risk of complications, even in people with poor control of their diabetes and early complications of diabetes. For this reason, people with IDDM are encouraged to do the best they can to keep their blood sugar levels as close to the normal range as possible.

However, intensive treatment does increase the risk of low blood sugar episodes, or hypoglycemia, and is not recommended for everyone, particularly older adults, children under age 13, people with heart problems or advanced complications, and people with a history of frequent severe hypoglycemia. Your doctor should help you decide if intensive control is right for you. There is more information about hypoglycemia here.

Points to remember

The DCCT showed that intensive control of blood sugar levels can help reduce the risk of complications associated with diabetes. The study showed that any sustained lowering of blood sugar levels is helpful.

Health Care Providers

Diabetes requires daily attention, and you need to learn how to care for your diabetes. A number of people can help you:

A doctor experienced in treating diabetes. These doctors are called endocrinologists or diabetologists. They will work with you to develop an individualized management routine and help you determine your ideal blood sugar range and ways to stay within that range.

"People with IDDM should be under the care of, or have regular contact with, a diabetes specialist who is up to date on diabetes and its management," advises Dr. Julio Santiago, an endocrinologist with the DCCT Center at Washington University in St. Louis. "During the last 10 years, diabetes care has greatly improved and become more complex. Services offered by diabetes specialists help people with IDDM learn the nuts and bolts of modern care and its benefits," he says.

A diabetes educator.

Diabetes educators specialize in teaching people how to manage their diabetes. Most are registered nurses, pharmacists, dietitians, or physician assistants with advanced training and experience. They help you and your physician develop a management plan based on your age, school or work schedule, daily activities, and eating habits. They can teach you the importance of good nutrition, exercising regularly, and testing your blood sugar. These professionals can also help you adjust to having diabetes. Diabetes educators who use the initials C.D.E. (Certified Diabetes Educator) after their names have passed an examination qualifying them to provide health education to people with diabetes.

A nutritionist or dietitian.

Nutritionists or dietitians trained in diabetes care provide diet guidelines and meal planning advice. They can teach you how to balance food intake and insulin requirements and how to handle special situations such as low blood sugar (hypoglycemia) and sick days. Some dietitians are also C.D.E.'s.

A mental health professional.

A person with diabetes can never take a vacation from daily management chores. For this and other reasons, diabetes can affect the way a person feels. If you need advice on managing diabetes during stressful or difficult times, or if having diabetes makes you feel sad or depressed, talking to a social worker, psychologist, or psychiatrist may be helpful.

"These professionals are trained to help people cope with chronic conditions that require constant care," says Dr. Alan Jacobson, a psychiatrist at the Joslin Diabetes Center in Boston. Dr. Jacobson, who counseled volunteers at the DCCT center at Joslin, says "Discussing their problems and anxieties with a professional helped DCCT volunteers feel emotionally and physically in control."

If a mental health professional is not available to you, Dr. Jacobson suggests joining a local diabetes support group. "Talking with someone else who has IDDM may help," he advises. Information about support groups is available from your physician or C.D.E. and local offices of the American Diabetes Association (ADA) and Juvenile Diabetes Foundation (JDF) International. These organizations also can provide suggestions on how to form a support group if one does not exist in your community. The addresses of these organizations are located here.

Daily Insulin

People with IDDM must give themselves insulin every day. Insulin cannot be taken in pill form. It can be injected, which involves use of a needle and syringe, or it can be given by an insulin pump. Insulin pumps are worn outside the body on a belt or in a pocket. They deliver a steady supply of insulin through a tube that connects to a needle placed under the skin. Extra amounts of insulin are taken before meals, depending on the blood glucose level and food to be eaten.

Another injection aid is an insulin pen. This device contains a replaceable insulin cartridge and a sterile, disposable needle. Insulin pens are handy because they eliminate the need for carrying extra syringes and insulin bottles. Jet injectors can also be used to give insulin, but these devices are expensive. A jet injector uses high pressure rather than a needle to propel insulin through the skin and into the tissue. Researchers are exploring the use of implantable pumps and other devices for giving insulin. Talk to your doctor about the insulin delivery system that is best for you.

The amount of insulin you need depends on your height, weight, age, food intake, and activity level. Insulin doses must be balanced with meal times and activities, and dosage levels can be affected by illness, stress, or unexpected events. Your doctor or diabetes educator will calculate how much insulin you should take each day to keep your blood sugar levels from rising too high or falling too low. They also will advise you about handling special situations. Most people with newly diagnosed IDDM can begin to inject their own insulin and estimate their insulin dosage needs within the first few days after instruction by a diabetes educator.

Points to remember

All people with IDDM need insulin. Ways to give insulin include:

  • A needle and syringe
  • An insulin pump
  • An insulin pen
  • A jet injector.

Blood Glucose Monitoring

Since the early 1980's, self-monitoring of blood glucose (SMBG) has been shown to be the best way to determine if the blood sugar levels of a person with IDDM are too high or too low. The measurement helps you monitor your diabetes control to determine if adjustments in diet, insulin, or exercise are needed. Although SMBG may at first seem difficult and adds to the expense of treatment, diabetes management has improved greatly since this testing method became widely available.

SMBG involves taking a drop of blood, usually from the tip of a finger, and placing it on a specially coated strip. Strips are "read" either visually or by a meter. Visually read strips change color according to the amount of sugar in the blood. The color is then compared to a color chart provided with the strips. To use a glucose meter, you insert the strip into the meter and it gives a digital reading of your blood sugar level, usually within a minute.

Using a blood glucose meter is a more accurate way to test blood sugar. SMBG meters available since the early 1990's offer many features. Some are small and lightweight, and some can store blood sugar readings for a few days or weeks. Meters are sold in drug stores or in diabetes supply stores. You should consult your diabetes educator about which meter would be most appropriate for your lifestyle. Before using a meter, you should receive instructions from a health care professional on how to operate and maintain the device. Correct use of the meter is necessary to obtain accurate readings.

It is important to follow the manufacturer's recommendations for testing the accuracy of your meter (called calibrating the meter). Failure to do so could cause inaccurate test readings, leading to errors in management.

Results of blood sugar measurements should be recorded in a diabetes diary available through pharmacies and doctors' offices. The books have space for recording events such as extra activities or sickness that may affect blood sugar levels. This information will help you and your doctor adjust insulin doses or make other changes in care, if necessary. Sometimes the diary may show patterns in blood sugar levels that indicate a need to contact a health professional between office visits.

Frequent SMBG was an important tool in the DCCT. "For volunteers in the intensive management group, blood glucose testing results served as a guidepost to making decisions about food intake and insulin doses in order to achieve better control," says Ms. Patricia Callahan, a DCCT diabetes nurse educator at the International Diabetes Center in Minneapolis. "Blood glucose testing should be done at least four times a day or as often as necessary to achieve optimal control," she advises. "The idea is to use your SMBG to make adjustments in your food, exercise, and insulin so that your blood sugar stays in a range that is best for you." Another blood test, the hemoglobin A1c test, shows the average level of blood sugar for the past 2 to 3 months. Your blood sample is sent to a laboratory for analysis. You should have a hemoglobin A1c test at least every 3 months. Based on the results, you and your physician will know how well you have been doing in controlling your diabetes over the last few months.

Points to remember

Blood glucose testing is very important for monitoring daily care.

  • SMBG shows current blood sugar levels.
  • Hemoglobin A1c tests average blood sugar levels over the past 2 to 3 months.

Robert is a 38-year-old father and construction worker. He has IDDM and understands the need to test his blood sugar levels often. When Robert wakes up in the morning, he tests his blood sugar level before injecting his insulin and eating breakfast. He also tests his blood sugar level before lunch, dinner, bedtime, and at other times, as necessary. Robert carries his blood glucose meter with him at all times. Daily, he writes down the results of his blood glucose tests and insulin doses. He brings these records to his doctor so they can discuss the results and make any necessary changes.

Meal Plans

Like everyone else, people with IDDM should follow a healthy eating plan. Your meal plan should be low in fat and cholesterol because these foods have been linked to heart disease, a common problem in people with diabetes. Children and pregnant women with diabetes may have additional nutritional needs. Guidelines for nutrition are available from your dietitian, diabetes educator, or the ADA. Organizations that can help you find resources for nutritional giudance are listed on page 35 of this booklet.

Different foods have different effects on blood sugar. Therefore, you should try to be as consistent as possible in your food choices and eating times. Some foods raise blood sugar quickly; others have a more gradual effect. By testing your blood sugar after eating, you can learn how particular foods affect your blood sugar levels.

Timing of meals and coordinating them according to your insulin injections is important. Regular insulin, for example, has its peak glucose-lowering effect approximately 2 hours after injection and acts for 4 to 6 hours. It is usually given before meals. Other insulin preparations are absorbed more slowly and have a longer duration of action.

Insulin regimens should be designed to fit a person's eating habits and lifestyle and should be as consistent as possible on a day-to-day basis. A dietitian can personalize a meal plan to include foods you like. Your physician and diabetes educator can also help.

The DCCT volunteers on intensive treatment learned about the relationship between food choices and blood sugar levels. "Each individual's insulin needs were adjusted to fit his or her lifestyle and diet, rather than trying to match the diet to fit the insulin," says Ms. Linda Delahanty, a dietitian with the DCCT Center at Massachusetts General Hospital in Boston. By understanding the relationship between food choices and blood sugar levels, she notes, volunteers in the intensive therapy group had more flexibility in their daily lives and could adjust their insulin doses to changes in their food intake and activity levels.

Points to remember

  • Consult with a dietian to develop a meal plan for you.
  • Learn how different foods affect your blood sugar levels.
  • Try to keep insulin injections, meals, and activities as consistent as possible on a day-to-day basis.

Jake has IDDM and is getting ready to go to college. He is planning to live off campus. For the first time, Jake will have to cook his own meals and shop for food. He consulted a dietitian to learn how to choose healthy foods and prepare balanced meals. His dietitian taught him how different foods could affect his blood sugar levels and gave him tips for preparing nutritious meals that fit into his busy schedule.


People with IDDM are encouraged to exercise for the same reasons as people without diabetes. Exercise keeps the body in tone and is good for the heart and lungs. Before exercising you should check your blood sugar levels because exercise tends to lower blood sugar. If your blood sugar is too low or if some time has passed since you ate, you should eat a snack before exercising. Sometimes exercise can cause very high blood sugar to rise even higher. If your blood sugar is over 300 mg/dl (before eating), you should give yourself insulin or wait until your blood sugar level falls before beginning to exercise.

"Exercise is an important part of the patient's management plan. Participation in sports and regular exercise helps to improve overall physical fitness," says Dr. Santiago. An exercise program should be planned with the help of a doctor or an experienced physical therapist or trainer.

Points to remember Exercise can lower blood sugar levels quickly. Before beginning exercise:

  • Check your blood sugar levels.
  • If your blood sugar is on the low side, eat a snack.
  • If your blood sugar is very high, you should bring it under control before beginning to exercise.
  • It may also be necessary to lower your insulin dose before planned exercise.

Sally, an 8-year-old with IDDM, loves to do gymnastics with her friends in the youth gymnastics league. She practices at the local gym every day for an hour. Before Sally exercises she checks her blood sugar level to make sure it is okay to start her workout. If her blood sugar level is too low, she eats a snack before beginning her gymnastics routine.

How Should Diabetic Emergencies Be Handled?

People with diabetes must always balance food, exercise, and insulin to control blood sugar levels. When this balance is disrupted, certain emergency conditions, including low blood sugar (hypoglycemia) or high blood sugar (hyperglycemia) may result. People with IDDM should always wear a medical identification bracelet, necklace, or watch band. These tags state that the wearer has IDDM and list a telephone number to call for help.


Very low blood sugar, called hypoglycemia, is sometimes referred to as an "insulin reaction." This condition can be caused by too much insulin, too little or delayed food, exercise, alcohol, or any combination of these factors. When hypoglycemia occurs, a person can become cranky, tired, sweaty, hungry, confused, and shaky. If blood sugar levels drop too low, a person can lose consciousness or experience a seizure.

Hypoglycemia can usually be treated quickly by eating or drinking something with sugar in it, such as a sweetened drink or orange juice. You should always carry a high-sugar snack that can be used to treat an insulin reaction. Special products to treat insulin reactions, including glucose tablets and gels, are available in drugstores.

If a person loses consciousness or cannot swallow because of hypoglycemia, medical help is necessary. Dial 911 or take the person to a hospital emergency room. An injectable medication called glucagon, available by prescription in drugstores, raises blood sugar quickly. A family member or friend should learn when and how to inject glucagon in an emergency. Your doctor, diabetes educator, or dietitian can give advice about treating hypoglycemia. In the DCCT, volunteers on intensive treatment had three times as many episodes of hypoglycemia severe enough to require help from another person as the volunteers on standard therapy. Because of this potential danger, intensive management is not recommended for everyone, particularly older adults, children under age 13, or people with heart problems or advanced complications. People who do not experience the usual symptoms of low blood sugar, a condition known as hypoglycemia unawareness, need to take extra care to avoid hypoglycemia. They should measure their blood glucose more often, particularly before driving or operating dangerous machinery.

Points to remember

  • Hypoglycemia is low blood sugar.
  • Hypoglycemia can develop quickly, especially with exercise.
  • Always carry a high-sugar snack to treat low blood sugar.
  • Hypogycemia, if not treated in time, can lead to uncon-sciousness.
  • Test blood sugar levels to avoid hypoglycemia,particularly before driving or exercising.

Lisa is 17 years old and has IDDM. She competes on her high school's track team. Her team practices in the late afternoon after classes. Lisa carries a book bag every day to school to hold her blood glucose meter and its supplies, extra sources of sugar, her lunch, and her books. She tests her blood sugar before lunch and before late afternoon practice.

Once when she ate a light lunch, she began to experience hypoglycemia while practicing. Lisa's coach recognized her clumsiness and confusion as symptoms of low blood sugar and quickly gave her a can of regular cola. A few minutes later she felt better, measured her blood sugar, and finished practice. Lisa's coach was able to prevent a dangerous situation from developing because she had been taught about the symptoms and treatment of hypoglycemia.


Hyperglycemia is the opposite of hypoglycemia. Hyperglycemia occurs when the body has too much sugar in the blood. This condition may be caused by insufficient insulin, overeating, inactivity, illness, stress, or a combination of these factors. The symptoms of hyperglycemia include extreme thirst, frequent urination, fatigue, blurred vision, vomiting, and weight loss.

If your blood sugar levels are above 250 mg/dl before meals, you should test your urine for ketones. Ketones are chemicals that the body makes when insulin levels are very low and excessive amounts of fat are being burned. Ketone buildup over several hours can lead to serious illness and coma, a condition called ketoacidosis. Ketone testing kits are available in drugstores or at doctors' offices. They should be available for you to use at home when you are ill or when your blood sugar is very high. Signs of ketoacidosis include vomiting, weakness, rapid breathing, and a sweet breath odor.

Points to remember Hyperglycemia is high blood sugar. Hyperglycemia develops more slowly than hypoglycemia. Hyperglycemia can indicate that ketoacidosis may be present. If blood sugar is high, test urine for ketones.

How Does Diabetes Affect Your Body?

Diabetes can cause damage to both large and small blood vessels, resulting in complications affecting the kidneys, eyes, nerves, heart, and gums. The DCCT showed that maintaining blood sugar levels as close to normal as possible prevents or slows the development of many of these complications.

Kidney Disease

Diabetic kidney disease, called diabetic nephropathy, can be a life-threatening complication of IDDM in about 40 percent of people who have had diabetes for 20 or more years. The kidneys are vital to good health because they serve as a filtering system to clean waste products from the blood. Diabetic nephropathy develops when the small blood vessels that filter these wastes are damaged. Sometimes this damage causes the kidneys to stop working. This condition is called kidney failure or end-stage renal disease. People with kidney failure must either have their blood cleaned by a dialysis machine or have a kidney transplant.

High blood pressure (hypertension) also increases a person's chance of developing kidney disease. People with diabetes are more likely to develop high blood pressure than people without diabetes. Therefore, keeping blood pressure under control is especially important for someone with IDDM. Your doctor should check your blood pressure at every visit.

Blood pressure tests measure how hard your heart is working to pump blood to the organs and vessels in your body. If blood pressure is too high, it can be treated with a doctor's help. Left untreated, bladder and kidney infections can also harm the kidneys. Consult your doctor if symptoms such as painful urination occur.

An early sign of kidney disease is albumin or protein in the urine. A doctor should test your urine for protein or albumin once a year. The doctor should also do an annual blood test to evaluate kidney function. More frequent tests may be necessary if findings are not normal.

The DCCT proved that intensive therapy can prevent the development and slow the progression of early diabetic kidney disease. Another recent study has shown that a type of medication called an ACE inhibitor can help protect the kidneys from damage.

Kevin is a 35-year-old sales representative and has IDDM. He visits his endocrinologist several times a year to have his blood pressure checked and his hemoglobin A1c measured. Once a year, the doctor takes a blood test to measure Kevin's cholesterol level and his kidney function. The doctor also asks Kevin to collect his urine in a container over a 24-hour period to check for protein or albumin in his kidneys. Albumin or protein in the urine is an early sign of diabetic kidney disease.

Eye Disease

Diabetes can affect the small blood vessels in the back of the eye, a condition called diabetic retinopathy. Retinopathy means disease of the retina, the tissue at the back of the eye that is sensitive to light. Diabetes eventually causes changes in the tiny vessels that supply the retina with blood. These small changes are called background retinopathy. Most people who have had diabetes for a number of years have background retinopathy, which usually does not affect sight. Over time, the blood vessels may rupture or leak fluid. In a minority of patients, most often those with higher blood sugar, retinopathy becomes more severe and new blood vessels may grow on the retina. These vessels may bleed into the clear gel, or vitreous, that fills the eye or detach the retina from its normal position because of bleeding or scar formation.

Laser treatment can help restore vision impaired by diabetic retinopathy. If you have had IDDM for 5 years or more, you should see an eye doctor at least once a year for an examination through dilated pupils. An annual exam is the best way to detect and treat eye damage before the condition becomes severe. Laser treatment, as well as surgical procedures performed by eye doctors who specialize in diabetic problems, can often help preserve useful vision even in cases of advanced retinopathy.

In the DCCT, intensive management reduced the risk of diabetic eye disease by 76 percent in participants with no eye damage at the beginning of the study. In those with early retinopathy, intensive therapy slowed the progression of eye damage by 50 percent.

Joan is a 40-year-old artist. She has had IDDM for 20 years. Every year she visits her ophthalmologist to have her eyes checked for diabetic eye disease. Her doctor dilates Joan's pupils and looks into her eyes carefully to detect any changes that may have occurred since her last visit. They discuss diabetic retinopathy and the importance of yearly check-ups to detect and treat any eye problems that may occur. Although Joan has very mild diabetic changes in her eyes, these changes do not pose a threat to her vision and are not likely to progress if she stays in excellent diabetic control.

Nerve Disease

Nerve disease caused by diabetes is called diabetic neuropathy. There are three types of nerve disease: peripheral, autonomic, and mononeuropathy. Peripheral neuropathy affects the hands, feet, legs, toes, or fingers. A person's feet, legs, and fingertips may lose feeling, burn, or become painful. To relieve the pain, doctors prescribe pain-killing drugs and sometimes antidepressant drugs. Scientists are studying other substances to help relieve pain associated with diabetic peripheral neuropathy.

Because of the loss of feeling associated with peripheral neuropathy, feet are especially vulnerable. You should check your feet carefully each day for cuts, bruises, and sores. If you notice anything unusual, see a doctor as soon as possible because foot infections and open sores can be difficult to treat in people with diabetes. Your doctor should check your feet at every visit. At least once a year, the doctor should check your neurological function by testing how well you sense temperature, pinprick, and vibration in your feet and changes of position in your toes. Your doctor may recommend that you see a foot care specialist, called a podiatrist.

Another type of nerve disease that may occur after several years of diabetes is called autonomic neuropathy. Autonomic neuropathy affects the internal organs such as the heart, stomach, sexual organs, and urinary tract. It can cause digestive problems and lead to incontinence (a loss of ability to control urine or bowel movements), and sexual impotence. A doctor can help diagnose problems associated with internal organs and may prescribe medication to help relieve pain and other problems associated with autonomic neuropathy. Mononeuropathy is a form of nerve disease that affects specific nerves, most often in the torso, leg, or head. Mononeuropathy may cause pain in the lower back, chest, abdomen, or in the front of one thigh. Sometimes, this nerve disease can cause aching in the eye, an inability to focus the eye, or double vision.

Mononeuropathy may also cause facial paralysis, a condition called Bell's palsy, or problems with hearing. Mononeuropathies occur most often in older people and can be quite painful. Usually the symptoms improve in weeks or months without causing long-term damage.

Lowering blood sugar levels may help prevent or reduce early neuropathy. DCCT study results showed the risk of significant nerve damage was reduced by 60 percent in persons on intensive treatment.

Every time Joe, who is a 45- year-old mail carrier and has IDDM, visits his doctor, he takes off his shoes and socks so his doctor does not forget to check his feet for sores, ulcers, and wounds. The doctor also checks his nerve reflexes and sense of feeling. Joe and his doctor discuss ways to prevent foot and nerve problems. Since Joe has lost some of his ankle reflexes and toe sensation, the doctor also stresses the importance of not smoking, not going barefoot, and keeping blood sugar levels under control.

Cardiovascular Disease

As with high blood pressure, heart disease is more common in people with diabetes than in people without diabetes. People with diabetes tend to have more fat and cholesterol in their arteries. The arteries are the large blood vessels that keep the heart beating and the blood flowing. When too much fat and cholesterol build up in the arteries, the arteries and heart must work harder. Over time, this extra work can lead to a heart attack. To help avoid heart problems, you should have your blood cholesterol and triglyceride levels checked once a year. Other risk factors that may cause the heart to become overworked include high blood pressure, smoking, age, extra weight, and lack of exercise. People with diabetes are also at greater risk for stroke and other forms of large blood vessel disease. A stroke is the result of damage to the blood vessels that circulate blood in the brain. Blockage of major blood vessels in the feet, legs, or arms is called peripheral vascular disease. Peripheral vascular disease causes poor circulation and can contribute to foot and leg ulcers.

DCCT participants were checked regularly for heart disease and related problems, although they were not expected to have many heart-related problems because of their young age. Volunteers in the intensive treatment group had fewer heart attacks and significantly lower risks of developing high blood cholesterol, which causes heart disease. The risk was 35 percent lower in these volunteers, suggesting that intensive treatment can help prevent heart disease. The DCCT volunteers on intensive therapy are being followed closely for the next 10 years to see if their risk of heart disease is reduced.

Points to remember

To reduce the risk of heart disease:

  • Do not smoke.
  • Eat a diet low in fat and high in fruits and vegetables.
  • Have your blood pressure checked regularly.
  • Have your cholesterol checked regularly.

Periodontal (Gum) Disease

People with diabetes, especially those with poor control of their blood sugar, are at risk for developing infections of the gum and bone that hold the teeth in place. Like all infections, gum infections can cause blood sugar to rise and make diabetes harder to control.

Periodontal disease starts as gingivitis, which causes sore, bleeding gums. If not stopped, gingivitis can lead to serious periodontal disease that can damage the bone that holds the tooth in its socket. Without treatment, teeth may loosen and fall out.

Good blood sugar control lowers the risk of gum disease. People with good control have no more gum disease than people without diabetes. Good blood sugar control, daily brushing and flossing, and regular dental check-ups are the best defense against gum problems.

Points to remember

Take special care of your teeth and gums.

  • Visit your dentist every 6 months.
  • Brush and floss teeth at least twice daily.
  • Practice other dental care guide-lines recommended by the dentist or dental hygienist.

How Should Special Situations Be Handled?

Illness, Stress, and Surgery

Illness and stress can affect blood sugar levels in people with diabetes. Therefore, during times of illness and stress, you need to be extra careful about keeping blood sugar levels in control. If you develop an illness such as the flu or strep throat, keep in touch with your doctor, test your blood sugar levels often, and check your urine for ketones. Even if you are feeling too sick to eat or have trouble keeping food down, you should continue giving yourself some insulin. In such situations, your doctor will tell you how much insulin to take as well as liquid diets to follow.

A doctor or diabetes nurse educator can also provide guidelines on how to handle stress. If you need hospitalization for an illness or require surgery, doctors and hospital personnel should know that you have diabetes. Your diabetes doctor should also be informed about the hospitalization and should be part of the team that monitors your care. Your doctor will give you advice regarding who to call in case of illness, vomiting, or very high blood sugar levels. In many cases, an early telephone call can prevent lengthy hospitalization.


Before the 1950's, most pregnant women with diabetes had little chance of having a normal baby. Since the 1960's major advances in diabetes treatment have taken place in Europe and North America. Today, with careful planning, most women with diabetes can become pregnant and deliver a healthy baby with the help of their doctors. Women with diabetes need to discuss their plans with their physicians before they become pregnant. Several studies show that excellent blood glucose control is important at the time a women becomes pregnant. Careful control during the first 2 months of pregnancy can reduce the risk of major birth defects. Later, during the third to ninth months of pregnancy, excellent blood glucose control is essential to protect the health of the baby and reduce complications related to premature delivery.

If you are a pregnant woman with IDDM, you should be treated by a team of doctors or at a center that specializes in the treatment of diabetic pregnancies. The center can provide guidelines for handling such pregnancy-related problems as morning sickness as well as closely monitor your baby before, during, and after delivery.

Because pregnancy sometimes can affect the eyes, kidneys, and blood pressure, your doctors will need to check your eyes, kidneys, and blood pressure before and throughout the pregnancy.

Points to remember

  • Most women with IDDM can have successful pregnancies.
  • Blood sugar levels should be in good control before a woman becomes pregnant.
  • Women with IDDM must be under the close care of specialists experienced in diabetic pregnancies.

Maria, a 25-year-old woman who has IDDM, wanted children. She and her husband visited her doctor for guidance. Maria's doctor said that before she conceived, her blood sugar levels should be in very good control and her kidneys, eyes, and blood pressure must be checked. Maria began a strict diabetes management schedule. She checked her blood sugar levels four times a day, ate healthy meals, began a walking routine, and had numerous blood and urine tests to make sure her body was healthy enough to carry a baby.

Once Maria became pregnant, she continued watching her diabetes carefully and visiting her doctor regularly. She spent a great deal of time monitoring her diabetes to make sure she and her baby would be healthy. Maria's hard work paid off because after 9 months she gave birth to a healthy baby boy.

School and Social Activities

Children with IDDM can attend school, do homework, play with friends, and participate in clubs or sports. However, special attention should be paid to diabetes care while the child is in school and involved in daily activities. If old enough, children may keep a blood glucose meter at school or with the school nurse. To safeguard against hypoglycemia, the child can carry extra snacks, or snacks can be given to the teacher for use in case the child's blood sugar level drops. Teachers, friends, club leaders, school nurses, or coaches should be aware that a child has diabetes and should know the signs of low blood sugar and how to treat it in case of emergency.

Points to remember

  • Inform teachers and school staff that your child has diabetes and how to treat hypoglycemia.
  • Always bring extra snacks in case hypoglycemia occurs with exercise.

Just like people without diabetes, people with diabetes can go to parties and participate in social activities. Some helpful tips are:
  • Call ahead to see what foods the host or hostess will serve and at approximately what time. This will help you keep track of how much food you should eat or how much insulin you will need.
  • If there does not seem to be food you should eat, offer to bring a snack that everyone, including you, can enjoy.
  • Make sure you bring your blood glucose meter to the party to check blood sugar levels before participating in any physical activities, such as strenuous dancing.

Adults with diabetes, even those with IDDM, can drink alcohol safely in moderation. Moderation usually means one or two occasional drinks taken with food. Drinking on an empty stomach and at bedtime can cause blood sugar levels to drop quickly, causing hypoglycemia, with symptoms of shakiness, dizziness, and confusion. People who do not know that someone has diabetes may mistake these symptoms for drunkenness. A dietitian can give guidelines about using alcohol and how to include it in a meal plan. People with nerve damage due to diabetes should avoid frequent alcohol use.

Points to remember

  • Alcohol can lower blood glucose.
  • Always eat when drinking alcohol.
  • Drink in moderation.
  • If you have nerve damage due to diabetes, avoid regular alcohol use.

What Is Happening in Diabetes Research?

The DCCT was one of many recent research programs supported by the Federal Government and by nongovernment organizations to improve the health and well-being of people with diabetes and to find ways to prevent and cure the disorder. A 10-year follow-up to the DCCT, the Epidemiology of Diabetes Intervention and Complications Study, is focusing on the development of macrovascular and renal complications in DCCT volunteers.

The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) conducts basic and clinical research in its own laboratories and supports research at centers and hospitals throughout the United States. Other institutes of the National Institutes of Health support studies on diabetic eye, heart, vascular, and nerve disease; pregnancy and diabetes; dental complications; and the immunological aspects of diabetes. This research has led to improved treatments for the complications of diabetes and ways to prevent complications from occurring.

Preventing Diabetes

Researchers are searching diligently for the causes of all forms of diabetes and ways to delay or prevent the disorder. Much progress has been made. Scientists have identified antibodies in the blood that make a person susceptible to IDDM, making it possible to screen relatives of people with diabetes and determine their risk for developing the disease.

A new NIDDK clinical trial, the Diabetes Prevention Trial-Type 1 (DPT-1), began in 1994. It is identifying relatives at risk for developing IDDM and treating them with low doses of insulin or with oral insulin-like agents in the hope of preventing IDDM. Similar research is being conducted at other medical centers throughout the world. These studies are based on encouraging results in laboratory animals with IDDM and on pilot studies in relatives of people with IDDM.

Advances in Managing Diabetes

In the past 15 years, many advances have improved treatment for people with diabetes:

Genetically engineered insulin.
Because it is identical to insulin produced by the human body, genetically engineered insulin is less apt to cause skin and other allergic reactions. Supplies of genetically engineered insulin are readily available.

Self-monitoring of blood glucose.
By testing your own blood sugar, you enable your doctor to offer you much better treatment than was available before 1980 when testing urine for glucose was the only way of estimating diabetes control.

Hemoglobin A1c testing.
Using one blood test, doctors can now monitor your average blood sugar control over a period of 2 to 3 months. This test tells you how well you are doing and whether any changes are needed in your management routine.

Insulin pumps, insulin pens, and other aids for administering insulin.
Insulin pumps, including implantable pumps now under development, can supply insulin in a more natural pattern, similar to the way the pancreas in a person without diabetes makes insulin. Other injection aids make giving insulin easier and more convenient than in the past, even in young children and people who are visually impaired.

Other improvements in diabetes management being developed include insulin in the form of nasal sprays, patches, or pills and devices to test blood sugar levels without having to prick a finger to get a blood sample. Perhaps one of the most important advances has been the development of an entirely new approach to diabetes management in which IDDM patients take responsiblity for much of their own care.

Curing Diabetes

Transplantation of the pancreas or of the insulin-producing islets of the pancreas offer a hope for a cure for IDDM. Many people with IDDM have had successful pancreas transplants, and a few have had islet transplants. Unfortunately, pancreas and islet transplants cannot be offered to everyone with diabetes as yet. The body's immune system rejects "foreign" or transplanted tissue, and people who have transplants must take powerful drugs to prevent rejection. These drugs are costly and may cause serious health problems. Therefore, pancreas or islet transplants are usually given only to people who have had or require a kidney transplant because of advanced complications and are already taking drugs to prevent rejection.

Researchers are working to develop less harmful drugs and better methods of transplanting pancreatic tissue to prevent rejection by the body, such as encapsulating the islet cells in a semi-permeable membrane that offers protection from immune attack, implanting the cells in the thymus gland to induce tolerance by the immune system, and using bioengineering techniques to create artificial islet cells that secrete insulin in response to increased sugar levels in the blood.

Clinical Trials

Clinical trials are one way to test new treatments that emerge from basic research. NIDDK plans and supports clinical trials related to diabetes, such as the DCCT and DPT-Type 1. For information about NIDDK-supported clinical trials, contact the National Diabetes Information Clearinghouse (NDIC), at the address and telephone number below.

Other medical centers also conduct clinical studies. The best way to find out about studies in progress is to contact a nearby university-affiliated hospital or large medical center. Additional information can also be obtained from a local chapter of the American Diabetes Association or Juvenile Diabetes Foundation.

Other Resources

The following organizations offer educational materials about diabetes and can help you find support groups and education programs in your community, including family activities and camp programs for children. Local affiliates and chapters of these organizations often can identify health professionals such as diabetologists, certified diabetes educators, and dietitians in the community. To locate affiliates and chapters of these organizations, consult your local telephone directory, or contact the following national offices:

American Association of Diabetes Educators
444 N. Michigan Avenue
Suite 1240
Chicago, IL 60611
(800) 832-6874

American Diabetes Association
ADA National Service Center
1660 Duke Street
Alexandria, VA 22314
(800) 232-3472

Juvenile Diabetes Foundation International
120 Wall Street
New York, NY 10005-4001
(212) 785-9500
(800) JDF-CURE
Fax: (212) 785-9595

American Dietetic Association
216 W. Jackson Blvd.
Chicago, IL 60606-6995
(800) 366-1655

Additional publications about diabetes are available from the National Diabetes Information Clearinghouse. The clearinghouse can also provide information about research and clinical trials supported by the National Institutes of Health. The address and telephone number are:

National Diabetes Information Clearinghouse
1 Information Way
Bethesda, MD 20892-3560

For more information about improving blood sugar control, write:

National Diabetes Outreach Program
1 Diabetes Way
Bethesda, MD 20892-3600


Our thanks to: Julio Santiago, M.D., of Washington University for his careful review of this etext.

We also wish to acknowledge the contributions of: Patricia Callahan, R.N., B.S., C.D.E. Linda Delahanty, M.S., R.D. Alan Jacobson, M.D.

NIH Pub. No. 94-2098
October 1994

etext last updated: 10 February 1997

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