Diabetes mellitus type 1
Diabetes (medically known as diabetes mellitus) is the name given to disorders in which the body has trouble regulating its blood glucose, or blood sugar, levels. There are two major types of diabetes: type 1 diabetes and type 2 diabetes. Type 1 diabetes, also called juvenile diabetes or insulin-dependent diabetes, is a disorder of the body's immune system -- that is, its system for protecting itself from viruses, bacteria or any "foreign" substances. Type 1 diabetes diagnosed in adults over 30 may be Latent Autoimmune Diabetes in Adults (LADA), sometimes known as Type 1.5 diabetes. LADA is often misdiagnosed as type 2 diabetes because of age; however people with LADA do not have insulin resistance like those with type 2. LADA is characterized by age, a lack of family history of type 2 diabetes, a gradual increase in insulin requirements, positive antibodies, and decreasing ability to make insulin as indicated by a low C-peptide. A fourth and very rare form of diabetes, called monogenic diabetes, is also sometimes mistaken for type 1 diabetes but typically strikes newborns.
Type 1 diabetes occurs when the body's immune system attacks and destroys certain cells in the pancreas, an organ about the size of a hand that is located behind the lower part of the stomach. These cells - called beta cells - are contained, along with other types of cells, within small islands of endocrine cells called the pancreatic islets. Beta cells normally produce insulin, a hormone that helps the body move the glucose contained in food into cells throughout the body, which use it for energy. But when the beta cells are destroyed, no insulin can be produced, and the glucose stays in the blood instead, where it can cause serious damage to all the organ systems of the body.
For this reason, people with type 1 diabetes must take insulin in order to stay alive. This means undergoing multiple injections daily, or having insulin delivered through an insulin pump, and testing their blood sugar by pricking their fingers for blood six or more times a day. People with diabetes must also carefully balance their food intake and their exercise to regulate their blood sugar levels, in an attempt to avoid hypoglycemic (low blood sugar) and hyperglycemic (high blood sugar) reactions, which can be life threatening.
Some people will have no symptoms before they are diagnosed with diabetes.
Others may notice these symptoms as the first signs of type 1 diabetes, or when the blood sugar is high:
• Feeling tired or fatigued
• Feeling hungry
• Being very thirsty
• Urinating more often
• Losing weight without trying
• Having blurry eyesight
• Losing the feeling or feeling tingling in your feet
For others, warning symptoms that they are becoming very sick may be the first signs of type 1 diabetes, or may happen when the blood sugar is very high:
• Deep, rapid breathing
• Dry skin and mouth
• Flushed face
• Fruity breath odor
• Nausea or vomiting, unable to keep down fluids
• Stomach pain
Low blood sugar (hypoglycemia) can develop quickly in people with diabetes who are taking insulin. Symptoms typically appear when the blood sugar level falls below 70 mg/dL. Watch for:
• Rapid heartbeat (palpitations)
Type 1 diabetes usually develops when the immune system destroys the insulin-producing cells (called the beta cells) in the pancreas. This is called an autoimmune response. The cause of this abnormal immune response is being studied.
This process occurs over many months or years, and there may be no symptoms of diabetes. High blood sugar and its associated symptoms (frequent urination, thirst) do not usually occur until more than 90 percent of the cells that make insulin have been destroyed.
Type 1 diabetes can develop in people with a family history of type 1 diabetes, but it also develops in people with no family history of diabetes. In either case, people who develop diabetes have one or more genes that make them susceptible to the disease. Environmental factors, such as exposure to certain viruses and foods early in life, might trigger the autoimmune response.
Close relatives (children, siblings) of a person with type 1 diabetes have an increased risk of developing type 1 diabetes, compared to a person with no family history (5 to 6 percent versus 0.4 percent, respectively).
Genetic testing can help to determine if a family member is at risk of developing diabetes. However, these tests are currently only available to people who participate in a clinical research trial.
To date, no intervention has been developed that can unequivocally prevent the development of type 1 diabetes or arrest the progression of immune system destruction of β-cells after diagnosis, although some promising studies have given the field much encouragement. The potential benefits of such interventions are clear: preservation of islet mass, even when it is insufficient to maintain normal glucose homeostasis, results in a clinical scenario in which diabetes is much easier to regulate in terms of glucose excursions and is accompanied by fewer episodes of potentially dangerous hypoglycemia. Obviously, earlier intervention, before the autoimmune process has begun or early enough to prevent significant islet loss, holds the promise of true diabetes prevention.
Although prediction of type 1 diabetes remains complex and actively investigated, models using antibody screening are currently used to drive diabetes prevention trials. In addition, several trials have reported modest utility in diabetes reversal. Although strategies that prevent diabetes may not be potent enough to reverse disease, it is likely that therapies that achieve diabetes reversal may be useful in diabetes prevention. As mentioned above, the goals for diabetes prevention depend in part on when during the pathogenesis of disease the intervention is applied. In the late stages of diabetes progression (or with reversal), several goals must be achieved including deactivation of islet-reactive lymphocytes, correction of the inflammatory milieu that injures islets and promotes lymphocyte activation, and restoration of an adequate islet mass. In earlier stages of diabetes prevention, it remains possible that these interventions may be effective even if applied singly. The following sections consider the current state of each of these strategies based on completed and ongoing trials and proposals.
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.
• Hemoglobin A1c test -- this test has been used in the past to help patients monitor how well they are controlling their blood glucose levels. In 2010, the American Diabetes Association recommended that the test be used as another option for diagnosing diabetes and identifying pre-diabetes. Levels indicate:
• Normal: Less than 5.7%
• Pre-diabetes: Between 5.7% and 6.4%
• Diabetes: 6.5% or higher
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
The following tests will help you and your doctor monitor your diabetes and prevent complications of diabetes:
• Check the skin and bones on your feet and legs.
• Check the sensation in your feet.
• Have your blood pressure checked at least every year (blood pressure goal should be 130/80 mm/Hg or lower).
• Have your glycosulated hemoglobin (HbA1c) checked every 6 months if your diabetes is well controlled; otherwise, every 3 months.
• Have your cholesterol and triglyceride levels checked yearly (aim for LDL cholesterol levels below 70-100 mg/dL).
• Get yearly tests to make sure your kidneys are working well (microalbuminuria and serum creatinine).
• Visit your ophthalmologist 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.
Diabetes is a lifelong disease for which there is not yet a cure. However, the outcome for people with diabetes varies. Studies show that tight control of blood glucose can prevent or delay complications to the eyes, kidneys, nervous system, and heart in type 1 diabetes. However, complications may occur even in those with good diabetes control.
After many years, diabetes can lead to serious problems with your eyes, kidneys, nerves, heart, blood vessels, and other areas in your body.
If you have diabetes, your risk of a heart attack is the same as someone who has already had a heart attack. Both women and men with diabetes are at risk. You may not even have the typical signs of a heart attack.
In general, complications include:
• Damage to the blood vessels that supply the legs and feet (peripheral vascular disease)
• Foot sores or ulcers, which can result in amputation
• High blood pressure
• High cholesterol
• Kidney disease and kidney failure (diabetic nephropathy)
• Macular edema
• Nerve damage, which causes pain and numbness in the feet, as well as a number of other problems with the stomach and intestines, heart, and other body organs (diabetic neuropathy)
• Worsening of eyesight or blindness due to diabetic retinopathy (eye disease)
Other complications include:
• Erection problems
• Infections of the skin, female genital tract, and urinary tract
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:
• Reduce symptoms
• Prevent diabetes-related complications such as blindness, kidney failure, nerve damage, amputation of limbs, and heart disease
You are the most important person in managing your diabetes. 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
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
People with type 1 diabetes should eat at about the same times each day and try to be consistent with the types of food they choose. This helps to prevent blood sugar from becoming extremely high or low.
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.
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 refers to being able to check your blood sugar at home yourself. Regular self-testing of your blood sugar tells you and your health care provider how well your diet, exercise, and diabetes medications are working. This is also called self-monitoring of blood glucose, or SMBG.
A health care provider or diabetes educator will help set up a testing schedule for you at home.
• Your doctor will help you set a goal for what level your blood sugar should be during the day.
• 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, under stress, or adjusting your insulin dosing.
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 a 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.
The American Diabetes Association recommends keeping blood sugar levels in a range that is based on your age. Discuss these goals with your physician and diabetes educator.
• 70 - 130 mg/dL for adults
• 100 - 180 mg/dL for children under age 6
• 90 - 180 mg/dL for children 6 - 12 years old
• 90 - 130 mg/dL for children 13-19 years old
• Less than 180 mg/dL for adults
• 110 - 200 mg/dL for children under age 6
• 100 - 180 mg/dL for children 6 - 12 years old
• 90 - 150 mg/dL for children 13 - 19 years old
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 can also damage blood vessels. Small sores or breaks in the skin may progress to deeper skin ulcers. Amputation of the affected limb may be needed when these skin ulcers do not improve or become larger or deeper.
To prevent problems with your feet, you should:
• Stop smoking if you smoke.
• Improve control of your blood sugar.
• Get a foot exam by your health care provider at least twice a year and learn whether you have nerve damage.
• Check and care for your feet EVERY DAY, especially if you already have known nerve or blood vessel damage or current foot problems.
• Make sure you are wearing the right kind of shoes.
Treating Low Blood Sugar
Hypoglycemia can develop quickly in people with diabetes. Symptoms typically appear when the blood sugar level falls below 70 mg/dL. If you have symptoms:
• Do a blood sugar check.
• If the level is low or you have symptoms of hypoglycemia, eat something with sugar: 4 ounces of fruit juice, 3 - 4 Lifesavers candies, or 4 ounces of regular soda. Overtreating a mild low blood sugar reaction can lead to problems with high blood sugar and difficult blood sugar control overall.
• Symptoms should go away within 15 minutes. If the symptoms don't go away, repeat the sugar-containing food as above, and test the sugar level again. When your blood sugar is in a safer range (over 70 mg/dL), you may need to eat a snack with carbohydrates and protein, such as cheese and crackers or a glass of milk.
Ask your doctor if you need a glucagon injection kit to raise blood sugar quickly in an emergency.
Medications To Prevent Complications
Your doctor may prescribe medications to reduce your chances of developing eye disease, kidney disease, and other conditions that are more common in people with diabetes.
An ACE inhibitor (or ARB) is often recommended as the first choice for those with high blood pressure and those with signs of kidney disease. ACE inhibitors include:
• Benazepril (Lotensin)
• Captopril (Capoten)
• Enalapril (Vasotec)
• Guinapril (Accupril)
• Lisinopril (Prinivil, Zestril)
• Perindopril (Aceon)
• Ramipril (Altace)
Statin drugs are usually the first choice to treat an abnormal cholesterol level. Aim for an LDL cholesterol level of less than 100 mg/dL (less than 70 mg/dL in high-risk patients).
Aspirin to prevent heart disease is most often recommended for people with diabetes who:
• Are older than 40
• Have a personal or family history of heart problems
• Have high blood pressure or high cholesterol