Type 1 Diabetes
Type 1 diabetes, once known as juvenile diabetes or insulin-dependent diabetes, is a chronic condition in which the pancreas produces little or no insulin, a hormone needed to convert sugar (glucose) into energy. Although type 1 diabetes can develop at any age, it typically appears during childhood or adolescence.
Type 2 diabetes is a similar — although much more common — condition in which the body becomes resistant to the effects of insulin or the body produces some, but not enough, insulin to maintain a normal blood sugar level.
Various factors may contribute to type 1 diabetes, including genetics and exposure to certain viruses. Despite active research, type 1 diabetes has no cure. But advances in blood sugar monitoring and insulin delivery have simplified the daily routine of managing type 1 diabetes. With proper treatment, people who have type 1 diabetes can expect to live long, healthy lives.
To understand type 1 diabetes, first you must understand how glucose is normally processed in the body.
Glucose is a main source of energy for the cells that make up your muscles and other tissues. Glucose comes from two major sources: the food you eat and your liver. During digestion, sugar is absorbed into the bloodstream. Normally, sugar then enters cells with the help of insulin.
The hormone insulin comes from the pancreas, a gland located just behind the stomach. When you eat, your pancreas secretes insulin into your bloodstream. As insulin circulates, it acts like a key by unlocking microscopic doors that allow sugar to enter your cells. Insulin lowers the amount of sugar in your bloodstream. As your blood sugar level drops, so does the secretion of insulin from your pancreas.
Your liver acts as a glucose storage and manufacturing center. When your insulin levels are low — when you haven't eaten in a while, for example — your liver releases the stored glucose to keep your glucose level within a normal range.
In type 1 diabetes, your immune system — which normally fights harmful bacteria or viruses — attacks and destroys the insulin-producing cells in the pancreas. This leaves you with little or no insulin. Instead of being transported into your cells, sugar builds up in your bloodstream.
The exact cause of type 1 diabetes is unknown. Genetics may play a role. Exposure to certain viruses may serve as a trigger as well.
Risk Factor :
Although the exact cause of type 1 diabetes is unknown, family history may play a role. Your risk of developing type 1 diabetes increases if you have a parent or sibling who has type 1 diabetes.
When to seek medical advice :
Consult your doctor if you're concerned about diabetes or if you notice any type 1 diabetes symptoms — increased thirst and frequent urination, extreme hunger, weight loss, fatigue or blurred vision.
If you're diagnosed with type 1 diabetes, you'll begin insulin therapy. You'll need close medical follow-up until your blood sugar level stabilizes and your doctor determines the proper dose of insulin. Once your blood sugar is under control, the doctor may recommend checkups every few months. A thorough yearly exam and regular foot and eye exams also are important — especially if your diabetes isn't well controlled, if you have high blood pressure or kidney disease, or if you're pregnant.
Type 1 diabetes symptoms may seem harmless at first. Look for :
- Increased thirst and frequent urination. As excess sugar builds up in your bloodstream, fluid is pulled from your tissues. This may leave you thirsty. As a result, you may drink — and urinate — more than usual.
- Extreme hunger. Without enough insulin to move sugar into your cells, your muscles and organs become depleted of energy. This triggers intense hunger that may persist even after you eat. Without insulin, the sugar in your food never reaches your energy-starved tissues.
- Weight loss. Despite eating more than usual to relieve hunger, you may lose weight — sometimes rapidly. Without the energy sugar supplies, your muscle tissues and fat stores may simply shrink.
- Fatigue. If your cells are deprived of sugar, you may become tired and irritable.
- Blurred vision. If your blood sugar level is too high, fluid may be pulled from your tissues — including the lenses of your eyes. This may affect your ability to focus clearly.
Various blood tests can be used to screen for diabetes, including :
- Random blood sugar test. A blood sample will be taken at a random time. Regardless of when you last ate, a random blood sugar level of 200 milligrams per deciliter (mg/dL) or higher suggests diabetes.
- Fasting blood sugar test. A blood sample will be taken after an overnight fast. A fasting blood sugar level between 70 and 100 mg/dL is normal. A fasting blood sugar level from 100 to 125 mg/dL is considered prediabetes, which indicates a high risk of developing diabetes. If it's 126 mg/dL or higher on two separate tests, you'll be diagnosed with diabetes.
If you're diagnosed with diabetes, your doctor may do other tests to distinguish between type 1 and type 2 diabetes — which may require different treatment strategies. Type 1 diabetes might be suspected if you have little or no ability to produce insulin, you have antibodies to insulin-producing cells in your blood, or you have toxic acids produced by the breakdown of fat (ketones) in your urine.
If you're diagnosed with diabetes, your doctor may also recommend a glycated hemoglobin (A1C) test. This blood test indicates your average blood sugar level for the past two to three months. It works by measuring the percentage of blood sugar attached to hemoglobin, the oxygen-carrying protein in red blood cells. The higher your blood sugar levels, the more hemoglobin you'll have with sugar attached. Generally, a target A1C result is 7 percent or less.
Type 1 diabetes can affect many major organs in your body, including your heart, blood vessels, nerves, eyes and kidneys. Keeping your blood sugar level close to normal most of the time can dramatically reduce the risk of these complications.
Short-term complications of type 1 diabetes require immediate care. Left untreated, these conditions can cause seizures and loss of consciousness (coma).
- High blood sugar (hyperglycemia). Your blood sugar level can rise for many reasons, including eating too much, being sick or not taking enough insulin. Check your blood sugar level often, and watch for signs and symptoms of high blood sugar — frequent urination, increased thirst, dry mouth, blurred vision, fatigue and nausea. If you have hyperglycemia, you'll need to adjust your meal plan, medications or both. If your blood sugar level is persistently above 250 mg/dL, consult your doctor right away or seek emergency care. You might have diabetic hyperosmolar syndrome, a life-threatening condition in which sky-high blood sugar causes blood to become thick and syrupy.
- Increased ketones in your urine (diabetic ketoacidosis). If your cells are starved for energy, your body may begin to break down fat. This produces toxic acids known as ketones. Watch for loss of appetite, nausea, vomiting, fever, stomach pain and a sweet, fruity smell on your breath — especially if your blood sugar level has been consistently higher than 250 mg/dL. You can check your urine for excess ketones with an over-the-counter ketones test kit. If you have excess ketones in your urine, consult your doctor right away or seek emergency care.
- Low blood sugar (hypoglycemia). If your blood sugar level drops below your target range, it's known as low blood sugar. Your blood sugar level can drop for many reasons, including skipping a meal, getting more physical activity than normal or injecting too much insulin. Check your blood sugar regularly, and watch for early signs and symptoms of low blood sugar — sweating, shakiness, weakness, hunger, dizziness and nausea. Later signs and symptoms include slurred speech, drowsiness and confusion.
If you develop hypoglycemia during the night, you might wake with sweat-soaked pajamas or a headache. Thanks to a natural rebound effect, nighttime hypoglycemia might cause an unusually high blood sugar reading first thing in the morning.
If you have signs or symptoms of low blood sugar, eat or drink something that will quickly raise your blood sugar level — fruit juice, glucose tablets, hard candy, regular (not diet) soda or another source of sugar. If you lose consciousness, a family member or close contact may need to give you an emergency injection of glucagon, a hormone that stimulates the release of sugar into the blood.
Long-term complications of type 1 diabetes develop gradually. The earlier you develop diabetes — and the less controlled your blood sugar — the higher the risk of complications. Eventually, diabetes complications may be disabling or even life-threatening.
- Heart and blood vessel disease. Diabetes dramatically increases your risk of various cardiovascular problems, including coronary artery disease with chest pain (angina), heart attack, stroke, narrowing of the arteries (atherosclerosis) and high blood pressure. In fact, about 75 percent of people who have diabetes die of some type of heart or blood vessel disease, according to the American Heart Association.
- Nerve damage (neuropathy). Excess sugar can injure the walls of the tiny blood vessels (capillaries) that nourish your nerves, especially in the legs. This can cause tingling, numbness, burning or pain that usually begins at the tips of the toes or fingers and over a period of months or years gradually spreads upward. Left untreated, you could lose all sense of feeling in the affected limbs. Damage to the nerves that control digestion can cause problems with nausea, vomiting, diarrhea or constipation. For men, erectile dysfunction may be an issue.
- Kidney damage (nephropathy). The kidneys contain millions of tiny blood vessel clusters that filter waste from your blood. Diabetes can damage this delicate filtering system. Severe damage can lead to kidney failure or irreversible end-stage kidney disease, requiring dialysis or a kidney transplant.
- Eye damage. Diabetes can damage the blood vessels of the retina (diabetic retinopathy), potentially leading to blindness. Diabetes also increases the risk of other serious vision conditions, such as cataracts and glaucoma.
- Foot damage. Nerve damage in the feet or poor blood flow to the feet increases the risk of various foot complications. Left untreated, cuts and blisters can become serious infections. Severe damage might require toe, foot or even leg amputation.
- Skin and mouth conditions. Diabetes may leave you more susceptible to skin problems, including bacterial infections, fungal infections and itching. Gum infections also may be a concern, especially if you have a history of poor dental hygiene.
- Osteoporosis. Diabetes may lead to lower than normal bone mineral density, increasing your risk of osteoporosis.
Treatment for type 1 diabetes is a lifelong commitment of monitoring blood sugar, taking insulin, maintaining a healthy weight, eating healthy foods and exercising regularly. The goal is to keep your blood sugar level as close to normal as possible to delay or prevent complications. In fact, tight control of blood sugar levels can reduce the risk of diabetes-related heart attacks and strokes by more than 50 percent.
If managing your diabetes seems overwhelming, take it one day at a time. And remember that you're not in it alone. You'll work closely with your diabetes treatment team — doctor, diabetes educator and registered dietitian — to keep your blood sugar level as close to normal as possible.
Blood sugar monitoring
Depending on what type of insulin therapy you select or require — single dose injections, multiple dose injections or insulin pump — you may need to check and record your blood sugar level up to four or more times a day. Careful monitoring is the only way to make sure that your blood sugar level remains within your target range.
Even if you take insulin and eat on a rigid schedule, the amount of sugar in your blood can change unpredictably. With help from your diabetes treatment team, you'll learn how your blood sugar level changes in response to :
- Food. What and how much you eat will affect your blood sugar level. Blood sugar is typically highest one to two hours after a meal.
- Physical activity. Physical activity moves sugar from your blood into your cells. The more active you are, the lower your blood sugar level. To compensate, you might need to lower your insulin dose before unusual physical activity.
- Medication. You need insulin to lower your blood sugar level. But any other medications you take may affect your blood sugar level as well, sometimes requiring changes in your diabetes treatment plan.
- Illness. During a cold or other illness, your body will produce hormones that raise your blood sugar level. This might require changes in your diabetes treatment plan.
- Alcohol. Alcohol can cause either high or low blood sugar, depending on how much you drink and if you eat at the same time.
- Stress. The hormones your body may produce in response to prolonged stress may prevent insulin from working properly.
- For women, fluctuations in hormone levels. As your hormone levels fluctuate during your menstrual cycle, so can your blood sugar level — particularly in the week before your period. Menopause may trigger fluctuations in your blood sugar level as well.
In addition to daily blood sugar monitoring, your doctor may recommend regular A1C testing to measure your average blood sugar level for the past two to three months. Compared with repeated daily blood sugar tests, A1C testing better indicates how well your diabetes treatment plan is working overall. An elevated A1C level may signal the need for a change in your insulin regimen or meal plan.
Insulin and other medications
Anyone who has type 1 diabetes needs insulin therapy to survive. Because stomach enzymes interfere with insulin taken by mouth, oral insulin isn't an option for lowering blood sugar. Often, insulin is injected using a fine needle and syringe or an insulin pen — a device that looks like an ink pen, except the cartridge is filled with insulin.
An insulin pump also may be an option. The pump is a device about the size of a cell phone worn on the outside of your body. A tube connects the reservoir of insulin to a catheter that's inserted under the skin of your abdomen. The pump is programmed to dispense specific amounts of insulin automatically. It can be adjusted to deliver more or less insulin depending on meals, activity level and blood sugar level.
Many types of insulin are available, including rapid-acting insulin, long-acting insulin and intermediate options. Examples include regular insulin (Humulin R, Novolin R, others), insulin isophane (Humulin N, Novolin N), insulin lispro (Humalog), insulin aspart (NovoLog) and insulin glargine (Lantus). Depending on your needs, your doctor may prescribe a mixture of insulin types to use throughout the day and night.
Inhaled insulin (Exubera) is now available as well. Inhaled insulin is a powdered form of insulin absorbed by the lungs through the use of a hand-held inhaler. Inhaled insulin is rapid acting, usually taken before a meal. It replaces only short-acting forms of injectable insulin — not the longer acting (basal) insulin that may be required as part of a diabetes treatment program.
Sometimes other medications are prescribed as well. For example, an injection of pramlintide (Symlin) before you eat can slow the movement of food through your stomach to curb the sharp increase in blood sugar that occurs after meals. Your doctor might prescribe low-dose aspirin therapy to help prevent heart and blood vessel disease.
Contrary to popular perception, there's no diabetes diet. You won't be restricted to a lifetime of boring, bland foods. Instead, you'll need plenty of fruits, vegetables and whole grains — foods that are high in nutrition and low in fat and calories — and fewer animal products and sweets. In fact, it's the best eating plan for the entire family. Even sugary foods are OK once in a while, as long as they're included in your meal plan.
Yet understanding what and how much to eat can be a challenge. A registered dietitian can help you create a meal plan that fits your health goals, food preferences and lifestyle. Once you've covered the basics, remember the importance of consistency. To keep your blood sugar on an even keel, try to eat the same amount of food with the same proportion of carbohydrates, proteins and fats at the same time every day.
Everyone needs regular aerobic exercise, and people who have type 1 diabetes are no exception. Get your doctor's OK to exercise. Then choose activities you enjoy, such as walking, swimming or biking. What's most important is making physical activity part of your daily routine. Aim for at least 30 minutes of aerobic exercise most days of the week. Stretching and strength training exercises are important, too. If you haven't been active for a while, start slowly and build up gradually.
Remember that physical activity lowers blood sugar. If you begin a new activity, check your blood sugar level more often than usual for a few weeks. You might need to adjust your meal plan or insulin doses to compensate for the increased activity.
The only potential cure for type 1 diabetes is a pancreas transplant. Other types of transplants are being studied as well.
- Pancreas transplant. With a successful pancreas transplant, you would no longer need insulin therapy. But pancreas transplants aren't always successful — and the procedure poses serious risks. You'd need a lifetime of potent immune-suppressing drugs to prevent organ rejection. These drugs can have serious side effects, including a high risk of infection and organ injury. Because the side effects can be more dangerous than the diabetes, pancreas transplants are usually reserved for people whose diabetes can't be controlled or those who have serious complications.
- Islet cell transplant. The islet cells are special cells in the pancreas that make insulin. Researchers are experimenting with islet cell transplants, which provide new insulin-producing cells from a donor pancreas. Although this experimental procedure has met with problems in the past, new techniques and better drugs to prevent islet cell rejection may hold promise for the future.
- Stem cell transplant. In a 2007 Brazilian study, a small number of people newly diagnosed with type 1 diabetes were able to stop using insulin after being treated with stem cells made from their own blood. Although stem cell transplants — which involve shutting down the immune system and then building it up again — can be risky, the technique may one day provide an additional treatment option for type 1 diabetes.
Type 1 diabetes can't be prevented. Researchers are studying various options for prevention, however.
For example, although oral insulin can't be used to lower blood sugar, researchers are testing whether an insulin capsule taken by mouth once a day can prevent or delay type 1 diabetes in people who have antibodies to insulin in their blood. In other studies, researchers are testing ways to slow the development of type 1 diabetes and preserve insulin production in people recently diagnosed with type 1 diabetes.