Diabetes also known medically as diabetes mellitus is a group of diseases that affect the way your body uses blood sugar (glucose). This sugar is vital to your health because it’s your body’s main source of fuel.
Normally, glucose is able to enter your cells because of the action of insulin a hormone secreted by your pancreas. Insulin acts like a key to unlock microscopic doors that allow glucose into your cells. But in diabetes mellitus, this process goes awry. Instead of being transported into your cells, glucose accumulates in your bloodstream and eventually is excreted in your urine. This usually occurs either because your body doesn’t produce enough insulin or because the cells don’t respond to insulin properly.
Diabetes mainly occurs in two forms:
This type develops when your pancreas makes little or no insulin. It affects between 5 percent and 10 percent of people with the disease.
This type is far more common than type 1, affecting between 90 percent and 95 percent of people with diabetes over age 20. It occurs when your body is resistant to the effects of insulin or your pancreas produces some, but not enough, insulin to maintain a normal glucose level.
More Americans have diabetes than ever before. According to the National Diabetes Statistics report, this disease affects 37.3 million adults and children, yet close to a third of them may not know they have it. That’s because diabetes can develop gradually over many years, often with no symptoms. Both types of diabetes are serious. The accumulation of glucose in your blood can damage almost every major organ in your body. Eventually, diabetes can be fatal. It’s the sixth leading cause of death in the United States.
No one has yet found a cure for diabetes mellitus. But the good news is that eating right, maintaining a healthy weight and getting plenty of exercise can help prevent the disease. And if you have diabetes, diet and exercise along with medications that control blood sugar can help you continue to live a healthy and active life.
Many people first learn they have diabetes through blood tests done for another condition or as part of a routine physical exam. But in some cases, diabetes may not be detected before damage to your eyes, kidneys or other organs has occurred. That’s why the American Diabetes Association recommends that all adults have a fasting blood glucose test at age 45. If the test results are normal, repeat the test every three years. If your results are borderline, have a fasting blood sugar test every year. Your doctor also may test for diabetes based on your symptoms or risk factors. Otherwise, doctors usually don’t screen for diabetes during routine visits.
Although the amount of sugar in your blood fluctuates, the range is relatively narrow. After fasting all night, most people have levels between 70 and 100 milligrams of glucose per deciliter of blood (mg/dL). That’s the equivalent of about 1 teaspoon of sugar in a gallon of water. If you consistently have fasting glucose levels above 126 mg/dL, you likely have diabetes. Tests that can detect diabetes include:
This test is fast, easy, inexpensive and requires a single drop of blood from a prick in your finger. Your blood is placed on a chemically treated strip that’s inserted into a machine that displays your blood sugar level. If your level is high more than 126 mg/dL have a more formal diagnostic test, such as the fasting blood glucose test.
This test is part of routine blood work done during a physical exam. Your blood is drawn through a needle inserted into a vein in your arm and sent to a laboratory for testing. Because you don’t necessarily fast for this test, you may just have eaten and your blood sugar may be high. Even so, it shouldn’t be higher than 200 mg/dL. If it is, your doctor will want to confirm the results by doing a fasting blood glucose test.
In general, your blood sugar is highest right after you eat and lowest after an overnight fast. That’s why the preferred way to test your blood sugar is after you’ve fasted overnight or for at least eight hours. For this test, blood is drawn from a vein in your arm and sent to a laboratory for analysis. If your fasting blood sugar measures 126 mg/dL or higher, your doctor may repeat the test. If the results of the second test are the same, you likely will be diagnosed with diabetes.
Often used to screen pregnant women for gestational diabetes, a glucose challenge test requires that you drink 8 ounces of an extremely sweet liquid after fasting for six hours. Your blood sugar is measured before you drink the liquid, then every hour for a three-hour period. If your blood sugar rises more than expected and doesn’t return to normal by the third hour, you likely have diabetes.
After you’ve received a diagnosis of diabetes, your doctor may order this test to measure your average blood glucose level for the previous two to three months. The test, also known as a hemoglobin A1C test, measures the amount of blood sugar attached to hemoglobin molecules the iron-rich molecules in red blood cells that deliver oxygen to your body. The higher your blood sugar levels, the more hemoglobin molecules you will have with sugar attached. In general, the life cycle of a red blood cell is 75 to 90 days, which is why the A1C test shows your average blood glucose levels for the past two to three months.
Controlling your blood sugar is essential to feeling healthy and avoiding long-term complications of diabetes. Some people are able to control their blood sugar with diet and exercise alone. Others may need to use insulin or other medications in addition to lifestyle changes. In either case, monitoring your blood sugar is a key part of your treatment program.
Pancreas or islet cell transplantation may be an option for people whose kidneys are failing or who aren’t responding to other treatments.
In recent years, researchers have focused increasing attention on transplantation for people with type 1 diabetes. Current procedures include:
Pancreas transplants have been performed since the late 1960s. Most are done in conjunction with or after a kidney transplant. Kidney failure is one of the most common complications of diabetes, and receiving a new pancreas when you receive a new kidney may actually improve kidney survival.
Furthermore, after a successful pancreas transplant, many people with diabetes no longer need to use insulin. Unfortunately, pancreas transplants aren’t always successful. Your body may reject the new organ days or even years after the transplant, which means you’ll need to take immunosuppressive drugs the rest of your life. These drugs are costly and can have serious side effects, including a high risk of infection and organ injury. Because the side effects can be more dangerous to your health than your diabetes, you’re usually not considered a candidate for transplantation unless your diabetes can’t be controlled or you’re experiencing serious complications. On the other hand, pancreas transplantation may be an option if you are age 45 or younger, have type 1 diabetes and need or have had a kidney transplant, or if insulin doesn’t control your blood sugar.
Your pancreas contains about 1 million islet cells, 75 percent to 80 percent of which produce insulin. The beta cells that produce insulin reside in the islets. Although still considered an experimental procedure, transplanting these cells may offer a less invasive, less expensive and less risky option than a pancreas transplant for people with diabetes. In islet cell transplantation, doctors infuse fresh pancreas cells into the liver of the person with diabetes. The cells spread throughout the liver and soon begin to produce insulin. The liver, not the pancreas, is the site of the transplant because it’s easier to access the large portal vein in your liver than it is to access a vein in your pancreas. What’s more, cells that grow in the liver secrete insulin much like cells in the pancreas do.
If you’ve just received a diagnosis of diabetes, monitoring your blood sugar may seem like an overwhelming task. But once you learn to measure your blood sugar and understand how important it is, you’ll feel more comfortable with the procedure and more in control of your disease. Testing is crucial because it tells you whether you’re keeping your glucose levels in the range you and your doctor have agreed on.
The best range for you depends on your age and the type of diabetes you have.
For younger adults who don’t have complications of diabetes, a typical target range might be 80 to 120 mg/dL before meals, and below 180 mg/dL after eating.
Older adults who have complications from their disease may have a fasting target goal of 100 to 140 mg/dL and below 200 mg/dL after meals. That’s because blood sugar that falls too low in older adults can be more dangerous than in younger people.
How often you test your blood sugar depends on the type of diabetes you have.
If you take insulin, test your blood sugar at least twice a day, and preferably three or four times a day. But if you have type 2 diabetes and don’t use insulin, you may need to test your blood sugar levels only once a day or as little as twice a week.
Keep in mind that the amount of sugar in your blood is constantly changing. Self-monitoring helps you learn what makes your blood sugar levels rise and fall, so you can make adjustments in your treatment. Factors that affect your blood sugar include:
Food raises your blood sugar level it’s highest one to two hours after a meal. What and how much you eat, and the time of day, also affect your blood sugar level.
In general, the more active you are, the lower your blood sugar. Physical activity causes sugar to be transported to your cells, where it’s used for energy, thereby lowering the levels in your blood. Aerobic exercises such as brisk walking, jogging or biking are especially good. But gardening, housework and even just being on your feet all day also can lower your blood sugar.
Insulin and oral diabetes medications deliberately work to lower your blood sugar. But medications you take for other conditions may affect glucose levels. Corticosteroids, in particular, may raise blood sugar levels. Medications such as thiazides, used to control high blood pressure, and niacin, used for high cholesterol, also may increase blood sugar. If you need to take certain high blood pressure medications, your doctor will likely make changes in your diabetes treatment.
The physical stress of a cold or other illness causes your body to produce hormones that raise your blood sugar level. The additional sugar helps promote healing. But if you have diabetes, this can be a problem. In addition, a fever increases your metabolism and how quickly sugar is utilized, which can alter the amount of insulin you need. For these reasons, be sure to monitor your glucose levels frequently when you’re sick.
Even a small amount of alcohol about 2 ounces can cause your sugar levels to fall too low. But sometimes alcohol can cause sugar levels to rise. If you choose to drink, do so only in moderation.
And monitor your blood sugar before and after consuming alcohol to see how it affects you. Also, keep in mind that alcohol counts as carbohydrate calories in your diet.
The female hormone estrogen typically makes cells more responsive to insulin, and progesterone makes cells more resistant. Although these two hormones fluctuate throughout the menstrual cycle, the majority of women don’t notice a corresponding change in blood sugar levels. Those who do are more likely to experience changes in blood sugar during the third week of their menstrual cycle, when estrogen and progesterone levels are highest.
Hormone levels also fluctuate during perimenopause the time before menopause. How this affects blood sugar varies, but most women can control any symptoms with additional exercise and changes in their diet. If your symptoms are more severe, your doctor may recommend oral contraceptives or hormone replacement therapy (HRT). After menopause, many women with diabetes require about 20 percent less medication because their cells are more sensitive to insulin.
Contrary to popular myth, there’s no “diabetes diet.” Furthermore, having diabetes doesn’t mean you have to eat only bland, boring foods. Instead, it means you’ll eat more fruits, vegetables and whole grains foods that are high in nutrition and low in fat and calories and fewer animal products and sweets. Actually, it’s the same eating plan all Americans should follow.
Yet understanding what and how much to eat can be a challenging task. Fortunately, a registered dietitian can help you put together a meal plan that fits your health goals, food preferences and lifestyle. Once you’ve decided on a meal plan, keep in mind that consistency is extremely important. To keep your blood sugar at a consistent level, try to eat the same amount of food with the same proportion of carbohydrates, proteins and fats at the same time every day.
But even with all the information you need and the best intentions, sticking to your diet can be one of the most challenging parts of living with diabetes. The key is to find ways to stay motivated. Don’t let others undermine your determination to eat in the healthiest way possible. You have to believe that what you’re doing matters and that you’re worth it.
Everyone needs regular aerobic exercise, and people with diabetes are no exception. The good news is that the same exercises that are good for your heart and lungs also help lower your blood sugar levels.
See your doctor before beginning any exercise program. Once you have the go-ahead, take some time to think about which activities you enjoy and are likely to stick with. Walking, hiking, jogging, biking, tennis, cross-country skiing and swimming are all good choices.
Aim for at least 30 minutes of aerobic exercise most days. But if you haven’t been active for a while, start slowly and build up gradually. For the best results, combine your aerobic activity with stretching and strength-training exercises.
Being overweight is the greatest risk factor for type 2 diabetes. That’s because fat makes your cells more resistant to insulin. But when you lose weight, the process reverses and your cells become more receptive to insulin. For some people with type 2 diabetes, weight loss is all that’s needed to restore blood sugar to normal. Furthermore, a modest weight loss of 10 to 20 pounds is often enough.
Yet losing even 10 pounds can be a challenge for most people. Fortunately, you don’t have to do it alone. A registered dietitian can help you develop a weight-loss plan that takes into account your current weight, activity level, age and overall health. Ultimately, however, the motivation has to come from you.
When diet, exercise and maintaining a healthy weight aren’t enough, you may need the help of medication. Medications used to treat diabetes include insulin. Everyone with type 1 diabetes and some people with type 2 diabetes must take insulin every day to replace what their pancreas is unable to produce. Unfortunately, insulin can’t be taken in pill form because enzymes in your stomach break it down so that it becomes ineffective. For that reason, many people inject themselves with insulin using a syringe or an insulin pen injector a device that looks like a pen, except the cartridge is filled with insulin. Others may use an insulin pump, which provides a continuous supply of insulin, eliminating the need for daily shots.
An insulin pump is a pumping device about the size of a deck of cards. You wear it outside your body. A small tube connects the reservoir of insulin to a catheter that’s inserted under the skin of your abdomen. The pump dispenses the desired amount of insulin into your body and can be adjusted to infuse more or less insulin depending on meals, activity and glucose level. Insulin pumps aren’t for everyone. But for some people they provide improved blood sugar control and a more flexible lifestyle.
The most widely used form of insulin is synthetic human insulin, which is chemically identical to human insulin but manufactured in a laboratory.
Unfortunately, synthetic human insulin isn’t perfect. One of its chief failings is that it doesn’t mimic the way natural insulin is secreted. But newer types of insulin, known as insulin analogs, more closely resemble the way natural insulin acts in your body. Among these are lispro (Humalog), insulin aspart (NovoLog) and glargine (Lantus).
A number of drug options exist for treating type 2 diabetes, including:
These medications stimulate your pancreas to produce and release more insulin. For them to be effective, your pancreas must produce some insulin on its own. Second-generation sulfonylureas such as glipizide (Glucotrol, Glucotrol XL), glyburide (
DiaBeta, Glynase PresTab, Micronase) and glimepiride (Amaryl) are prescribed most often. The most common side effect of sulfonylureas is low blood sugar, especially during the first four months of therapy. You’re at much greater risk of low blood sugar if you have impaired liver or kidney function.
These medications, such as repaglinide (Prandin), have effects similar to sulfonylureas, but you’re not as likely to develop low blood sugar. Meglitinides work quickly, and the results fade rapidly.
Metformin (Glucophage, Glucophage XR) is the only drug in this class available in the United States. It works by inhibiting the production and release of glucose from your liver, which means you need less insulin to transport blood sugar into your cells. One advantage of metformin is that is tends to cause less weight gain than do other diabetes medications. Possible side effects include a metallic taste in your mouth, loss of appetite, nausea or vomiting, abdominal bloating, or pain, gas and diarrhea. These effects usually decrease over time and are less likely to occur if you take the medication with food. A rare but serious side effect is lactic acidosis, which results when lactic acid builds up in your body.
Symptoms include tiredness, weakness, muscle aches, dizziness and drowsiness. Lactic acidosis is especially likely to occur if you mix this medication with alcohol or have impaired kidney function.
These drugs block the action of enzymes in your digestive tract that break down carbohydrates. That means sugar is absorbed into your bloodstream more slowly, which helps prevent the rapid rise in blood sugar that usually occurs right after a meal. Drugs in this class include acarbose (Precose) and miglitol (Glyset). Although safe and effective, alpha-glucosidase inhibitors can cause abdominal bloating, gas and diarrhea. If taken in high doses, they may also cause reversible liver damage.
These drugs make your body tissues more sensitive to insulin and keep your liver from overproducing glucose. Side effects of thiazolidinediones, such as rosiglitazone (Avandia) and pioglitazone hydrochloride (Actos), include swelling, weight gain and fatigue. A far more serious potential side effect is liver damage. The thiazolidinedione troglitzeone (Rezulin) was taken off the market in March 2000 because it caused liver failure. If your doctor prescribes these drugs, it’s important to have your liver checked every two months during the first year of therapy. Contact your doctor immediately if you experience any of the signs and symptoms of liver damage, such as nausea and vomiting, abdominal pain, loss of appetite, dark urine, or yellowing of your skin and the whites of your eyes (jaundice). These may not always be related to diabetes medications, but your doctor will need to investigate all possible causes.
By combining drugs from different classes, you may be able to control your blood sugar in several different ways. Each class of oral medication can be combined with drugs from any other class. Most doctors prescribe two drugs in combination, although sometimes three drugs may be prescribed. Newer medications, such as Glucovance, which contains both glyburide and metformin, combine different oral drugs in a single tablet.