Am I at Risk for Type 2 Diabetes: NIDDK

• What is diabetes?
• How can type 2 diabetes be prevented?
• What are the signs and symptoms of type 2 diabetes?
• Should I be tested for diabetes?
• What does it mean to be at risk for type 2 diabetes?
• What are my risk factors for developing type 2 diabetes?
• What can I do about my risk factors?
• Doing my part: Getting started
• Hope through research

Diabetes is a disease in which blood glucose levels are above normal. People with diabetes have problems converting food to energy. After a meal, food is broken down into a sugar called glucose, which is carried by the blood to cells throughout the body. Cells use a chemical known as insulin, made in the pancreas, to help them process blood glucose into energy.

People develop diabetes for two reasons: the pancreas does not make enough insulin for the body's needs, or the cells in the muscles, liver, and fat do not use insulin properly, or both. As a result, the amount of glucose in the blood increases while the cells are starved of energy. Over the years, high blood glucose damages nerves and blood vessels, leading to complications such as blindness, heart and kidney disease, nerve problems, gum infections, and amputation.

Although people with diabetes can prevent or delay complications by keeping blood glucose levels close to normal, preventing or delaying the development of diabetes in the first place is even better. The results of the Diabetes Prevention Program (DPP) show how to do so.

Types of diabetes

The three main kinds of diabetes are type 1, type 2, and gestational diabetes.

Type 1 diabetes

Type 1 diabetes, formerly called juvenile diabetes or insulin-dependent diabetes, is usually first diagnosed in children, teenagers, or young adults. In this form of diabetes, the beta cells of the pancreas no longer make insulin because the body's immune system has attacked and destroyed them. Treatment for type 1 diabetes includes taking insulin shots or using an insulin pump, making wise food choices, exercising regularly, taking aspirin daily, and controlling blood pressure and cholesterol.

Type 2 diabetes

Type 2 diabetes, formerly called adult-onset diabetes or noninsulin-dependent diabetes, is the most common form of diabetes. People can develop type 2 diabetes at any age--even during childhood. In type 2 diabetes, the pancreas does not make enough insulin and the fat, muscle, and liver cells do not use it properly. Being overweight and inactive can increase the chances of developing type 2 diabetes. Treatment includes taking diabetes medicines, making wise food choices, exercising regularly, taking aspirin daily, and controlling blood pressure and cholesterol.

Gestational diabetes

Some women develop gestational diabetes during the late stages of pregnancy. Although this form of diabetes usually goes away after the baby is born, a woman who has had it is more likely to develop type 2 diabetes later in life. Gestational diabetes is caused by the hormones of pregnancy or a shortage of insulin.

A recently concluded federally funded study of 3,234 people at high risk for diabetes, the Diabetes Prevention Program, showed that diet and exercise can sharply lower your risk of getting type 2 diabetes.

The DPP was a major clinical trial that studied ways to prevent or delay diabetes in people at high risk for type 2 diabetes. Participants were overweight and had higher than normal levels of blood glucose, called impaired glucose tolerance. Both conditions are strong risk factors for type 2 diabetes. Because of the high risk among some minority groups, about half of the DPP participants were African American, American Indian, Asian American, Pacific Islander, or Hispanic.

The DPP compared two approaches to preventing diabetes: an intensive healthy eating and exercise program and the diabetes drug metformin. People who engaged in moderate physical activity for about 30 minutes a day, followed a low-fat, low-calorie diet, and lost 5 to 7 percent of their body weight reduced their risk of getting type 2 diabetes by 58 percent, according to preliminary analysis of the results. Those receiving metformin reduced their risk by 31 percent.

Many people have no signs or symptoms. Symptoms can also be so mild that you might not even notice them. Five million people in the United States have type 2 diabetes and do not know it. Here is what to look for:

• increased thirst
• increased hunger
• fatigue
• increased urination, especially at night
• weight loss
• blurred vision
• sores that do not heal

Sometimes people have symptoms but do not suspect diabetes. They delay scheduling a checkup because they do not feel sick. Many people do not find out they have the disease until they have diabetes complications, such as blurry vision or heart trouble. It is important to find out early if you have diabetes because treatment can prevent damage to the body from diabetes.

If you are 45 years old or older, you need to get tested for diabetes, even if you do not have any of the risk factors listed below. If you are younger than 45 and have one or more risk factors, you should also get tested. Ask your doctor for a fasting blood glucose test. The results of this blood test will tell your doctor how much glucose is in your blood. Your doctor may ask you to have the test twice.

Even if your blood glucose level is normal and you have no risk factors, if you are over 45, you may need to remind your doctor to check your blood glucose again in 3 years. If you have at least one of the risk factors below, have your blood checked more frequently.

You are more likely to get type 2 diabetes if you are age 45 or older, are overweight, are inactive, or have high blood pressure or high cholesterol. You are also at high risk if diabetes runs in your family or if you are African American, American Indian, Asian American, Hispanic, or Pacific Islander. However, you can take steps to reduce your risk of developing diabetes.

To find out your risk for type 2 diabetes, check each item that applies to you.

If you checked one or more boxes, you are at risk for type 2 diabetes. If you checked more than three boxes, your chances of getting diabetes are high. It is important to lower your risk by working on the factors under your control.

You can do a lot to lower your chances of getting diabetes. Exercising regularly, reducing fat and calorie intake, and losing weight can all help you reduce your risk of developing type 2 diabetes. Lowering blood pressure and cholesterol levels also help you stay healthy.

If you checked

    I am overweight.

Then take these steps:

• Reach and maintain a reasonable body weight.
• Make wise food choices most of the time.
• Be physically active every day.

If you checked

    I am fairly inactive.

Then take this step:

• Be physically active every day.

If you checked

    My blood pressure is 140/90 or higher.

Then take these steps:

• Reach and maintain a reasonable body weight.
• Make wise food choices most of the time.
• Reduce your intake of salt and alcohol.
• Talk to your doctor about whether you need medicine to control your blood pressure.

If you checked

    My cholesterol levels are not normal.

Then take these steps:

• Make wise food choices most of the time.
• Be physically active every day.
• Talk to your doctor about whether you need medicine to control your cholesterol levels.

Making big changes in your life is hard, especially if you are faced with more than one change. You can make it easier by taking these steps:

• Make a plan to change behavior.
• Decide exactly what you will do and when you will do it.
• Plan what you need to get ready.
• Think about what might prevent you from reaching your goals.
• Find family and friends who will support and encourage you.
• Decide how you will reward yourself when you do what you have planned.

Your doctor, a dietitian, or a counselor can help you make a plan. Here are some of the areas you may wish to change to reduce your risk of diabetes.

Reach and maintain a reasonable body weight

Your weight affects your health in many ways. Being overweight can keep your body from making and using insulin properly. It can also cause high blood pressure. The DPP showed that losing even a few pounds can help reduce your risk of developing type 2 diabetes because it helps your body use insulin more effectively. In the DPP, people who lost between 5 and 7 percent of their body weight significantly reduced their risk of type 2 diabetes. For example, if you weigh 150 pounds, losing about 10 pounds would make a difference.

Body mass index (BMI) is a measure of body weight relative to height. You can use BMI to see whether you are underweight, normal weight, overweight, or obese. Use the body mass index table below to find your BMI.

• Find your height in the left-hand column.
• Move across in the same row to the number closest to your weight.
• The number at the top of that column is your BMI. Check the word above your BMI to see whether you are normal weight, overweight, or obese.

Source: Adapted from Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults: The Evidence Report.

* pdf versions require the free Adobe® Acrobat Reader software for viewing.

If you are overweight or obese, choose sensible ways to get in shape:

• Avoid crash diets. Instead, eat less of the foods you usually have. Limit the amount of fat you eat.
• Increase your physical activity. Aim for at least 30 minutes of exercise most days of the week. (See below for easy suggestions.)
• Set a reasonable weight-loss goal, such as losing 1 pound a week. Aim for a long-term goal of losing at least 7 percent of your total body weight.

Make wise food choices most of the time

What you eat has a big impact on your health. By making wise food choices, you can help control your body weight, blood pressure, and cholesterol.

• Take a hard look at the serving sizes of the foods you eat. Reduce serving sizes of main courses (such as meat), desserts, and foods high in fat. Increase the amount of fruits and vegetables.
• Limit your fat intake to about 25 percent of your total calories. For example, if your food choices add up to about 2,000 calories a day, try to eat no more than 56 grams of fat. Your doctor or a dietitian can help you figure out how much fat to have. You can check food labels for fat content too.
• You may also wish to reduce the number of calories you have each day. Your doctor or dietitian can help you with a meal plan that emphasizes weight loss.
• Keep a food and exercise log. Write down what you eat, how much you exercise--anything that helps keep you on track.
• When you meet your goal, reward yourself with a nonfood item or activity, like watching a movie.

Be physically active every day

Regular exercise tackles several risk factors at once. It helps you lose weight, keeps your cholesterol and blood pressure under control, and helps your body use insulin effectively. People in the DPP who were physically active for 30 minutes a day reduced their risk of type 2 diabetes. Many chose brisk walking for exercise.

If you are not very active, you should start slowly, talking with your doctor first about what kinds of exercise would be safe for you. Make a plan to increase your activity level toward the goal of being active for at least 30 minutes a day most days of the week.

Choose activities you enjoy. Here are some ways to work extra activity into your daily routine:

• Take the stairs rather than an elevator or escalator.
• Park at the far end of the lot and walk.
• Get off the bus a few stops early and walk the rest of the way.
• Walk or bicycle instead of drive whenever you can.

Take your prescribed medications

Some people need medication to help control their blood pressure or cholesterol levels. If you do, take your medicines as directed. Ask your doctor whether there are any medicines you can take to prevent type 2 diabetes.

We now know that regular exercise, weight loss, and a low-fat diet can prevent type 2 diabetes. However, scientists are still investigating whether type 1 diabetes can be prevented.

In the Diabetes Prevention Trial--Type 1, a study sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases, close relatives of people with type 1 diabetes are tested for their risk of getting the disease. Those at high risk will receive treatment that might prevent type 1 diabetes. More information about the study is available by calling 1-800-425-8361 or at www.niddk.nih.gov/patient/dpt_1/dpt_1.htm.

Other studies on preventing type 1 diabetes are under way. For up-to-date information on clinical trials, see clinicaltrials.gov.

National Diabetes Information Clearinghouse

The National Diabetes Information Clearinghouse (NDIC) is a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). The NIDDK is part of the National Institutes of Health under the U.S. Department of Health and Human Services. Established in 1978, the clearinghouse provides information about diabetes to people with diabetes and to their families, health care professionals, and the public. NDIC answers inquiries, develops and distributes publications, and works closely with professional and patient organizations and Government agencies to coordinate resources about diabetes.

Publications produced by the clearinghouse are carefully reviewed by both NIDDK scientists and outside experts. This booklet was reviewed by David G. Marrero, Ph.D., Indiana University School of Medicine, Diabetes Research and Training Center; and Michael L. Parchman, M.D., M.P.H., Associate Professor, Department of Family and Community Medicine, University of Texas Health Sciences Center.

This e-text is not copyrighted. The clearinghouse encourages users of this e-pub to duplicate and distribute as many copies as desired.

NIH Publication No. 02-4805
December 2001