Type 1 Diabetes

What is Type 1 Diabetes?

Type 1 diabetes is a chronic (lifelong) disease that occurs when the pancreas does not produce enough insulin to properly control blood sugar levels.

See also:

• Diabetes
• Gestational diabetes
• Type 2 diabetes

Alternative names

Insulin-dependent diabetes; Juvenile onset diabetes; Diabetes - type 1

Causes

Diabetes is a lifelong disease for which there is not yet a cure. There are several forms of diabetes. Type 1 diabetes is often called juvenile or insulin-dependent diabetes. In this type of diabetes, cells of the pancreas produce little or no insulin, the hormone that allows sugar (glucose) to enter body cells.

Without enough insulin, glucose builds up in the bloodstream instead of going into the cells. The body is unable to use this glucose for energy despite high levels in the bloodstream. This leads to increased hunger.

In addition, the high levels of glucose in the blood causes increased urination. This leads to excessive thirst. Within 5 - 10 years, the insulin-producing beta cells of the pancreas are completely destroyed and the body can not longer produce insulin.

Type 1 diabetes can occur at any age. Many patients, however, are diagnosed after age 20.

The exact cause is unknown. Genetics, viruses, and autoimmune problems may play a role.

Symptoms & Signs

Possible symptoms include:

• Abdominal pain
• Absence of menstruation
• Fatigue
• Increased thirst
• Increased urination
• Nausea
• Vomiting
• Weight loss despite increased appetite

Exams and Tests

Diabetes is diagnosed with the following blood tests:

• Fasting blood glucose level -- diabetes is diagnosed if it is higher than 126 mg/dL on two occasions
• Random (nonfasting) blood glucose level -- diabetes is suspected if it is higher than 200 mg/dL, and the patient has symptoms such as increased thirst, urination, and fatigue (this must be confirmed with a fasting test)
• Oral glucose tolerance test -- diabetes is diagnosed if the glucose level is higher than 200 mg/dL after 2 hours.

Ketone testing is also used in type 1 diabetes. Ketones are produced by the breakdown of fat and muscle. They are harmful at high levels. The ketone test is done using a urine sample. Ketone testing is usually done at the following times:

• When the blood sugar is higher than 240 mg/dL
• During an illness such as pneumonia, heart attack, or stroke
• When nausea or vomiting occur
• During pregnancy

People with diabetes should have their A1c (HbA1c) levels checked every 3 - 6 months. The HbA1c is a measure of average blood glucose during the past 2 - 3 months. It can help determine how well treatment is working.

Treatments

The immediate goals of treatment are to treat diabetic ketoacidosis and high blood glucose levels. Because type 1 diabetes can come on suddenly and the symptoms can be severe, newly diagnosed people may need to stay in the hospital.

The long-term goals of treatment are to:

• Prolong life
• Reduce symptoms
• Prevent diabetes-related complications such as blindness, kidney failure, heart disease, and amputation of limbs

These goals are accomplished through:

• Careful self-testing of blood glucose levels
• Education
• Exercise
• Foot care
• Insulin use
• Meal planning and weight control

INSULIN

Insulin lowers blood sugar by allowing it to leave the bloodstream and enter cells. Everyone needs insulin. People with type 1 diabetes can't make their own insulin. They must take insulin every day.

Insulin is usually injected under the skin. In some cases, a pump delivers the insulin continuously. Insulin does not come in pill form.

Insulin preparations differ in how fast they start to work and how long they last. The health care professional will review your blood glucose levels to determine the appropriate type of insulin you should use. More than one type of insulin may be mixed together in an injection to achieve the best blood glucose control.

The injections are needed, in general, from one to four times a day. People are taught how to give insulin injections by their health care provider or a diabetes nurse educator. At first, a child's injections may be given by a parent or other adult. By age 14, most children can be expected (but should not be required) to give their own injections.

People with diabetes need to know how to adjust the amount of insulin they are taking in the following situations:

• When they exercise
• When they are sick
• When they will be eating more or less food and calories
• When they are traveling

DIET

Meal planning for type 1 diabetes should be consistent, to allow food and insulin to work together to regulate blood glucose levels. If meals and insulin are out of balance, blood glucose levels can go up and down. (See: Diabetes diet)

The American Diabetes Association and the American Dietetic Association have information for planning healthy, balanced meals. It can help to talk with a registered dietitian or nutrition counselor.

PHYSICAL ACTIVITY

Regular exercise helps control the amount of sugar in the blood. It also helps burn excess calories and fat to achieve a healthy weight.

Ask your health care provider before starting any exercise program. Those with Type 1 diabetes must take special precautions before, during, and after intense physical activity or exercise.

• Always check with your doctor before starting a new exercise program.
• Ask your doctor or nurse if you have the right footwear.
• Choose an enjoyable physical activity that is appropriate for your current fitness level.
• Exercise every day and at the same time of day, if possible.
• Monitor your blood glucose levels at home before and after exercising.
• Carry food that contains a fast-acting carbohydrate in case your blood glucose levels get too low during or after exercise.
• Wear a diabetes identification bracelet and carry a cell phone to use in case of emergency.
• Drink extra fluids that do not contain sugar before, during, and after exercise.
• As you change the intensity or duration of your exercise, you may need to modify your diet or medication to keep your blood glucose levels in an appropriate range.

SELF-TESTING

Blood glucose monitoring is done by checking the glucose content of a small drop of blood. The testing is done on a regular basis and will let you know how well diet, medication, and exercise are working together to control diabetes.

The results can be used to adjust meals, activity, or medications to keep blood sugar levels within an appropriate range. Tests are usually done before meals and at bedtime. More frequent testing may be needed when you are sick or under stress.

Testing will provide valuable information so the health care provider can suggest improvements to your care and treatment. Testing will identify high and low blood sugar levels before serious problems develop.

A device called a glucometer can provide an exact blood sugar reading. There are different types of devices. Usually, you prick your finger with a small needle called a lancet to get a tiny drop of blood. You place the blood on a test strip and put the strip into the device. You should have results within 30 - 45 seconds.

Keeping accurate records of your test results will help you and your health care provider plan how to best control your diabetes.

FOOT CARE

Diabetes causes damage to the blood vessels and nerves. This can reduce your ability to feel injury to or pressure on the foot. You may not notice a foot injury until severe infection develops.

Diabetes also affects the body's immune system, decreasing the ability to fight infection. Small infections can rapidly progress to death of the skin and other tissues. Amputation may be needed.

To prevent injury to the feet, get into a routine of checking and caring for your feet daily. See: Diabetes foot care.

TREATING LOW BLOOD SUGAR

Low blood sugar is known as hypoglycemia. It can occur from too much insulin, too much exercise, or too little food. Hypoglycemia can develop quickly in people with diabetes. Symptoms typically appear when the blood sugar level falls below 70. Watch for:

• Headache
• Hunger
• Nervousness
• Shaking
• Sweating
• Weakness

If these symptoms occur and you have a blood sugar test kit available, do a blood sugar check. If the level is low, eat something with sugar: fruit juice, several teaspoons of sugar, a cup of skim milk, or regular soda. If you don't have a test kit handy, eat sugar anyway - it can't hurt. Symptoms should go away within 15 minutes. If the symptoms don't go away, eat more sugar and test the sugar level again.

AFTER the symptoms go away, you can eat more substantial food. Eat simple sugar first to get the situation under control. Even if you or your child is hungry, do not eat "real" food until the sugar level comes up. Real food won't produce enough sugar and takes too long to digest.

If you are a parent, relative, or friend of someone experiencing these symptoms, monitor the person closely. If symptoms become worse (confusion, seizures, or unconsciousness) give the person a shot of glucagon. If you don't have glucagon, call 911 immediately.

You should have some glucagon stored for emergencies. Make sure everyone in your home, as well as babysitters and caregivers, knows how to use it. Also check the expiration date.

Don't panic. Glucagon works very fast -- usually within 15 minutes. Lay the person on the side to prevent choking. If the person is not better in 15 minutes, call 911.

TREATING HIGH KETONES

When there is not enough insulin to move glucose into cells, glucose can build up in the blood. The body then looks for other forms of energy and uses fat as a fuel source. As fats are broken down, acids called ketones build up in the blood and urine. In high levels, ketones are poisonous. This condition is known as ketoacidosis.

You can check for ketones using a simple urine test available at pharmacies. This test should be done every 4 - 6 hours anytime a person with diabetes has a blood sugar level above 240. Also do the test if the person:

• Has a dry mouth, frequent urination, or vomiting
• Is sick
• Is nusually thirsty

The warning signs that ketoacidosis is getting serious might include:

• Deep, rapid breathing
• Dry skin and mouth
• Flushed face
• Fruity breath odor
• Nausea or vomiting
• Stomach pain

If these symptoms occur, call the doctor or go to the emergency room right away. If left untreated, this condition will lead to coma and even death.

EDUCATION

You are the most important person in managing your diabetes. Diabetes education involves learning how to live with your diabetes. It helps prevent complications.

You should know the basic steps to diabetes management:

• How to recognize and treat low blood sugar (hypoglycemia)
• How to recognize and treat high blood sugar (hyperglycemia)
• Diabetes meal planning
• How to give insulin
• How to monitor blood glucose and urine ketones
• How to adjust insulin and food intake during exercise
• How to handle sick days
• Where to buy diabetes supplies and how to store them

Where to get support

For additional information and resources, see diabetes support group.

Prognosis

The outcome for people with diabetes varies. Studies show that tight control of blood glucose can prevent or delay complications to the eyes, kidneys, and nervous system. However, complications may occur even in those with good diabetes control.

Possible Complications

Emergency complications include:

• Hypoglycemia
• Ketoacidosis

Long-term complications include:

• Erection problems
• Eye problems, including diabetic retinopathy, retinal detachment, glaucoma, and cataracts
• Foot problems, including skin changes, arterial insufficiency, neuropathy, and specific foot deformities (hallux valgus, bunion, hammertoe, and calluses)
• Infections of the skin, female genital tract, and urinary tract
• Kidney disease (diabetic nephropathy)
• Nerve damage (diabetic neuropathy)
• Stroke
• Vascular disease, including blocked arteries and heart attacks

When to contact a medical professional

If you are newly diagnosed with type 1 diabetes, you should probably have medical follow-up weekly until you have good control of blood glucose. Your health care provider will review the results of home glucose monitoring and urine testing. The provider will also look at your diary of meals, snacks, and insulin injections.

As the disease becomes more stable, follow-up visits will be less often. Visiting your health care provider is very important for monitoring possible long-term complications from diabetes.

Call your health care provider or go to the emergency room if you have these symptoms of ketoacidosis:

• Abdominal pain
• Deep and rapid breathing
• Increased thirst and urination
• Loss of consciousness
• Nausea
• Sweet-smelling breath

Go to the emergency room or call 911 if you have symptoms of severe hypoglycemia or insulin reaction:

• Confusion
• Convulsions or unconsciousness
• Dizziness
• Double vision
• Drowsiness
• Headache
• Lack of coordination
• Trembling
• Weakness

You can treat early signs of hypoglycemia at home by eating sugar or candy or taking glucose tablets. If your signs of hypoglycemia continue or if your blood glucose levels stay below 60 mg/dL, go to the emergency room.

Prevention

Currently, there is no way to prevent type 1 diabetes. There is no effective screening test for type 1 diabetes in people with no symptoms.

To prevent complications of diabetes, visit your health care provider or diabetes educator at least four times a year. Talk about any problems you are having.

Regularly have the following tests:

• Have your blood pressure checked every year (blood pressure goals should be 130/80 mm/Hg or lower).
• Have your glycosylated hemoglobin (HbA1c) checked every 6 months if your diabetes is well controlled, otherwise every 3 months.
• Have yourcholesterol and triglyceride levels checked yearly (aim for LDL levels below 100 mg/dL).
• Get yearly tests to make sure your kidneys are working well (microalbuminuria and serum creatinine).
• Visit your ophthalmologist (preferably one who specializes in diabetic retinopathy) at least once a year, or more often if you have signs of diabetic retinopathy.
• See the dentist every 6 months for a thorough dental cleaning and exam. Make sure your dentist and hygienist know that you have diabetes.
• Make sure your health care provider inspects your feet at each visit.

Stay up-to-date with all of your vaccinations and get a flu shot every year in the fall.

References

Alemzadeh R, Wyatt DT. Diabetes Mellitus. In: Kliegman RM, ed. Kliegman: Nelson Textbook of Pediatrics. 18th ed. Philadelphia, Pa: Saunders; 2007:chap 590.

American Diabetes Association. Standards of medical care in diabetes -- 2008. Diabetes Care. 2008;31:S12-S54.

Eisenbarth GS, Polonsky KS, Buse JB. Type 1 Diabetes Mellitus. In: Kornenberg HM, Melmed S, Polonsky KS, Larsen PR. Kronenberg: Williams Textbook of Endocrinology. 11th ed. Philadelphia, Pa: Saunders Elsevier;2008:chap 31.

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Review Date: 6/17/2008

Reviewed By: Elizabeth H. Holt, MD, PhD, Assistant Professor of Medicine, Section of Endocrinology and Metabolism, Yale University. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.