Topic Overview

What is prediabetes?

Prediabetes is a term that is used when you are at risk for type 2 diabetes. It means that your blood sugar is higher than it should be. Most people who get type 2 diabetes have prediabetes first. The good news is that lifestyle changes may help you get your blood sugar back to normal and avoid or delay diabetes.

Type 2 diabetes is a lifelong disease that happens when the pancreas can't make enough insulin and/or the body's tissues can't use insulin properly. Insulin is a hormone that helps the body’s cells use sugar (glucose) for energy. It also helps the body store extra sugar in muscle, fat, and liver cells.

Without insulin, the sugar can't get into the cells to do its work. It stays in the blood instead. This can cause high blood sugar levels. A person has diabetes when the blood sugar stays too high too much of the time.

Over time, high blood sugar can cause serious problems with the eyes, heart, blood vessels, nerves, and kidneys. High blood sugar also makes a person more likely to get serious illnesses or infections.

What causes prediabetes?

Doctors don't know exactly what causes prediabetes. People who are overweight, aren't physically active, and have a family history of diabetes are more likely to get prediabetes. Women who have had gestational diabetes are also more likely to get prediabetes.

What are the symptoms?

Most people with prediabetes don't have any symptoms. But if you have prediabetes, you need to watch for signs of diabetes, such as:

• Feeling very thirsty.
• Urinating more often than usual.
• Feeling very hungry.
• Having blurred vision.
• Losing weight without trying.

How is prediabetes diagnosed?

A blood test can tell if you have prediabetes. You have prediabetes if:

• The results of your hemoglobin A1c test are 5.7% to 6.4%.
• The results of your fasting blood glucose test are 6.1 to 6.9 millimoles per litre (mmol/L) or higher.
• The results of your oral glucose tolerance test (OGTT) are 7.8 to 11.0 mmol/L or higher (2 hours after the beginning of the test).

How is it treated?

The key to treating prediabetes and preventing type 2 diabetes is getting your blood sugar levels back to a normal range. You can do this by making some lifestyle changes.

• Watch your weight. If you are overweight, losing just a small amount of weight may help. Reducing fat around your waist is particularly important.
• Make healthy food choices.
  • Limit how much fat you eat, and try to eat foods that are high in fibre.
  • Try to eat about the same amount of carbohydrate at each meal. This helps keep your blood sugar steady. Carbohydrate affects blood sugar more than other nutrients. It is found in sugar and sweets, grains, fruit, starchy vegetables, and milk and yogourt.
  • Talk to your doctor, a diabetes educator, or a dietitian about an eating plan that will work for you. There are many ways to manage how much and when you eat.
• Be active. You can do moderate activity, vigorous activity, or both. Bit by bit, increase the amount you do every day. You may want to swim, bike, or do other activities. Walking is an easy way to get exercise.

Making these changes may help delay or prevent diabetes. You may also avoid or delay some of the serious problems that you can get when you have diabetes, such as heart attack, stroke, and heart, eye, nerve, and kidney disease.

Some doctors may use medicine to control blood sugar in people with prediabetes. If your doctor prescribed medicine to help control your blood sugar, take it as prescribed.

Can prediabetes be prevented?

Staying at a healthy weight, eating healthy foods, and getting regular exercise can help prevent prediabetes.

Frequently Asked Questions

Cause

Prediabetes occurs when your body isn't able to keep your sugar (glucose) at a normal level. Your blood sugar is higher than normal, but it's not high enough to be diabetes.

The food you eat turns into blood sugar, which your body uses for energy. Normally, the pancreas makes insulin, which allows the sugar in blood to get into the body's cells. But when your body can't use insulin the right way, the sugar doesn't move into cells. It stays in your blood instead. This is called insulin resistance.

The buildup of sugar in the blood causes prediabetes. If your blood sugar stays too high for too long, prediabetes can turn into type 2 diabetes.

People who are overweight, aren't physically active, and have a family history of diabetes are more likely to get prediabetes. Women who have had gestational diabetes are also more likely to get prediabetes.

Symptoms

Most of the time, prediabetes has no symptoms. But if you have prediabetes, you need to watch for signs of type 2 diabetes, such as:

• Feeling very thirsty.
• Urinating more often than usual.
• Feeling very hungry.
• Having blurred vision.
• Losing weight without trying.

What Happens

Prediabetes is a warning sign that you are at risk for getting type 2 diabetes.

It is estimated that 7 out of 10 people who have prediabetes will get type 2 diabetes.¹ Studies have shown that by losing weight and increasing physical activity, people can prevent or delay prediabetes from becoming diabetes.²

Over time, high blood sugar levels increase your risk for diabetes and heart disease, even if you're still healthy. Compared to people with normal blood sugar levels, people with prediabetes have a higher risk of heart attack or stroke.³

When you have prediabetes, you're also at higher risk for eye, nerve, kidney and heart disease, and for stroke.

One Man's Story: Jerry, 54 When he first found out he had prediabetes, Jerry felt angry and frustrated. His doctor told him to lose weight and get more exercise, or else run the risk of getting type 2 diabetes. "I thought, 'What's the point? I might still get diabetes.' I felt like I was stuck either way. But it turns out there's a lot you can do."—Jerry Read more about Jerry.

You can reduce your risk for type 2 diabetes and related health problems by making healthy lifestyle changes, such as:

• Watching your weight.
• Making healthy food choices.
• Being active.

For more information, see the Prevention section of this topic.

What Increases Your Risk

Risk factors

Things that can increase your chances of prediabetes are called risk factors. Some risk factors you can control, and others you can't.

The risk factors for prediabetes are similar to those for type 2 diabetes. Most people who get type 2 diabetes had prediabetes first. Risk factors include:⁴

• Being overweight.
• Lack of physical activity.
• Family history. If you have a parent, brother, or sister who has type 2 diabetes, you have a greater chance of getting the disease.
• Age. The risk for getting prediabetes and type 2 diabetes increases with age. But the number of children with type 2 diabetes is increasing. Usually, children who get type 2 diabetes have a family history of the disease, are overweight, and aren't physically active.
• Race and ethnicity. People of First Nations, African, Hispanic, South Asian, and Asian descent are at higher risk than whites for getting type 2 diabetes.
• History of gestational diabetes . Women who have had gestational diabetes or who have had a baby that weighed more than 4 kg (9 lb) at birth are at higher risk for type 2 diabetes later in life.
• Low birth weight. People who weighed less than 2.5 kg (5.5 lb) at birth are more likely to get type 2 diabetes later in life.

Other health problems that put you at risk for prediabetes and type 2 diabetes include:

• Polycystic ovary syndrome (PCOS). PCOS is a problem in which a woman's hormones are out of balance.
• Metabolic syndrome. This is a group of health problems that includes having high blood pressure, high cholesterol, and too much fat around the waist.

One Woman's Story: Linda, 39 With a family history of type 2 diabetes, Linda says she should have watched her weight more carefully. She wasn't too surprised by her prediabetes diagnosis. But she got motivated right away to do what she could about it. "I watched my mom inject herself with insulin every day. Sometimes she needed my help. She had the hardest time keeping her blood sugar down and figuring out what to eat. I don't want to go down that road if I can help it."—Linda Read more about Linda.

Reducing your risk

There are some things you can do to reduce your chances of getting prediabetes and diabetes:

• Watch your weight. Being overweight increases your risk for prediabetes and type 2 diabetes. Your risk also increases if most of your body fat is in your belly area. Losing even 5 to 10 percent of your body weight can reduce your risk.
• Make healthy food choices. Eating a balanced diet is one of the best things you can do for your health.
• Be active. The less you exercise, the greater your risk of getting prediabetes and type 2 diabetes.² The more active you are, the more sugar (glucose) your body uses for energy. This keeps the sugar from building up in your blood.
• If you smoke, quit. Quitting smoking can reduce your chances of having other health problems, such as heart attack and stroke.
• Keep high blood pressure and high cholesterol under control. Doing so can lower your risk of heart disease and large blood vessel disease.

When you have prediabetes, it's important to follow your treatment. This can reduce your risk of prediabetes turning into type 2 diabetes.

For more tips about things you can do to reduce your risk, see the Prevention section of this topic.

When to Call a Doctor

When you have prediabetes, it's important to watch for symptoms of type 2 diabetes. Call your doctor if you notice that you are:

• Feeling very thirsty a lot of the time.
• Urinating more often than usual.
• Feeling very hungry a lot of the time.
• Having blurred vision.
• Losing weight without trying.

If you haven't yet been diagnosed with prediabetes, you may want to talk to your doctor about testing. The Canadian Diabetes Association recommends testing for prediabetes, which may lead to type 2 diabetes, if you:⁴

• Are age 40 or older.
• Are younger than 40 and have risk factors for type 2 diabetes.

For more information, see the Examinations and Tests section of this topic.

Examinations and Tests

Who should be tested for prediabetes?

The Canadian Diabetes Association recommends screening for prediabetes, which may lead to type 2 diabetes, if you:⁴

• Are age 40 or older and you have never had your blood glucose (sugar) tested or you have not been tested in more than 3 years.
• Are younger than 40 and have risk factors for type 2 diabetes. These include:
  • High blood pressure.
  • High cholesterol. People with high cholesterol and high triglyceride levels are at risk for getting type 2 diabetes.
  • Family history of prediabetes or type 2 diabetes. People who have a parent, brother, or sister with prediabetes or type 2 diabetes are more likely to get the disease.
  • History of gestational diabetes. Women who have had gestational diabetes or who have had a baby that weighed more than 4 kg (9 lb) at birth are more likely to get type 2 diabetes.
  • Race and ethnicity. People of First Nations, African, Hispanic, South Asian, and Asian descent are at greater risk than whites for getting type 2 diabetes.

What tests will you have for prediabetes?

Your doctor will use a medical history, physical examination, and blood glucose testing to find out if you have prediabetes and are at risk for getting type 2 diabetes.

Blood tests used to identify prediabetes include:

• Hemoglobin A1c. This test estimates your blood sugar over the past 2 to 3 months.
• Fasting blood glucose test. This test is usually done after you fast overnight for 8 hours.
• Oral glucose tolerance test (OGTT). For an OGTT, your blood sugar is measured after fasting and then again 2 hours after you drink a special glucose liquid. This test is not done as often as the fasting glucose test, which is more convenient.

You have prediabetes if:

• The results of your A1c test are 5.7% to 6.4%.
• The results of your fasting blood glucose test are 6.1 to 6.9 millimoles per litre (mmol/L) or higher.
• The results of your oral glucose tolerance test (OGTT) are 7.8 to 11.0 mmol/L or higher (2 hours after the beginning of the test).

Phrases such as "a touch of diabetes," "borderline diabetes," and "your sugar is a little high" are unclear. If you hear these phrases, ask your doctor if your blood sugar level is in the prediabetes or diabetes range.

Tests for other health problems

If you are diagnosed with prediabetes, your doctor may also want to:

• Check your blood pressure.
• Do a blood test to check your cholesterol levels.
• Test your blood sugar regularly to check for type 2 diabetes.

Treatment Overview

Your treatment for prediabetes will focus on losing weight, eating right, and getting active. This is your chance to reverse prediabetes so it doesn't turn into type 2 diabetes. Doing these things will also help you avoid other health problems, such as heart disease and stroke, that are linked to diabetes.

You may also need to take diabetes medicine along with doing these things. But research has shown that over the long term, healthy lifestyle changes can work better than medicine at reducing your risk of getting type 2 diabetes.²

Watch your weight

Most people who have prediabetes are overweight and have a body mass index (BMI) of 25 or higher. To find out your BMI, use the Interactive Tool: Is Your Weight Increasing Your Health Risks?

If you have a BMI of 25 or higher, losing 5% to 10% of your body weight may help you prevent or delay type 2 diabetes.² For example, if you weigh 100 kilograms, losing 5 to 10 kilograms can reduce your risk for type 2 diabetes. It is especially helpful to lose belly fat.

A healthy weight helps your body use insulin the way it should. Losing weight can also lower insulin resistance in people who have prediabetes. The more you lose, the more you benefit, as long as you do it in a healthy way.

How you do it is up to you. One way to start is by making healthy eating changes that you can keep doing over time. Try reducing the number of calories you eat and drink and adding more activity to your day. For help, see the topic Weight Management.

One Man's Story: Jerry, 54 Jerry signed up for a weight-loss program and started a daily food diary to track what and when he ate. He added walks around the neighbourhood and visits to the gym to his routine. In 7 months, he dropped 11 kilograms—about 10% of his body weight. "It hasn't been easy. I've had some ups and downs, especially over the holidays. Hey, I love to eat. Sometimes it's hard to stay focused. But tracking what, when, and why I eat helps me to eat less."—Jerry Read more about Jerry.

Make healthy food choices

Eating a balanced diet is one of the best things you can do for yourself and for your health. Try to:

• Limit the amount of fat you eat. Eat foods low in saturated fat and high in soluble fibre.
• Cut calories.
• Limit sweets.

For help, see the topic Healthy Eating and:

Healthy Eating: Starting a Plan for Change.

Healthy Eating: Cutting Unhealthy Fats From Your Diet.

Diabetes: Using a Plate Format for Eating.

Get active

The more active you are, the more sugar (glucose) your body uses for energy. This keeps the sugar from building up in your blood. Exercise can also improve insulin resistance.

Try to do moderate to vigorous activity for at least 2½ hours a week.⁵ It's fine to be active in blocks of 10 minutes or more throughout your day and week.

Moderate activity is safe for most people, but it's always a good idea to talk to your doctor before you start an exercise program. For more help, see the topic Fitness and:

Quick Tips: Getting Active At Home.

Fitness: Adding More Activity to Your Life.

Fitness: Walking for Wellness.

One Woman's Story: Linda, 39 Linda works full-time, has three young children, and has zero time for the gym. So when she learned she had prediabetes, she had to find creative ways to fit activity into her day. For example, after dinner she turns up the stereo and does dance moves while washing dishes, putting food away, and cleaning the kitchen. "It takes about a half-hour and is a great workout. My kids get a big kick out of it too."—Linda Read more about Linda.

Take medicine if you need to

You may need to take an oral medicine, such as metformin. It reduces the amount of sugar made by the liver in people who are insulin resistant.

If you do need medicine, be sure to take it as directed. For more information, see the Medications section of this topic.

If you smoke, quit

Quitting smoking can help you reduce your risk for type 2 diabetes and avoid other health problems that make diabetes worse. Quitting can also reduce your risk of heart attack and stroke.

Watch blood pressure and cholesterol levels

When you have prediabetes, you are more likely to get heart disease than someone with normal blood sugar levels. High cholesterol is also linked to an increased risk for type 2 diabetes.³ So it's important to keep your blood pressure and cholesterol under control. For help, see:

Therapeutic Lifestyle Changes (TLC) for high cholesterol.

High Blood Pressure: Checking Your Blood Pressure at Home.

Prevention

Even if you have risk factors for prediabetes, you can still take steps to prevent the disease. And if you already have prediabetes, these same steps can keep it from turning into type 2 diabetes.

Your risk for prediabetes is higher if you are overweight and physically inactive. So:

• Watch your weight. Losing 5% to 10% of your body weight may help you prevent or at least delay type 2 diabetes.² For example, if you weigh 100 kilograms, losing 5 to 10 kilograms can reduce your risk. Losing weight can be hard, but you can do it. The easiest way to start is by cutting calories and getting more active. For help, see the topic Weight Management.
• Make healthy food choices. It can be hard to make big changes in the way you eat. It's okay to start small, by limiting the amount of fat you eat and by eating more fruits, vegetables, and fibre. For help, see the topic Healthy Eating and:

  Healthy Eating: Cutting Unhealthy Fats From Your Diet.

  Healthy Eating: Changing Your Eating Habits.

• Be active. When you're active, your body uses glucose. The more active you are, the more glucose your body uses for energy. This keeps the sugar from building up in your blood. Exercise can also improve insulin resistance. Walking is a great way to start. For help, see the topic Fitness and:

  Quick Tips: Getting Active At Home.

  Fitness: Adding More Activity to Your Life.

• If you smoke, quit. Quitting smoking can help you reduce your risk of getting type 2 diabetes and other health problems.⁶ Quitting can also reduce your risk of heart attack and stroke. For help, see:

  Quitting Smoking: Getting Support.

• Keep blood pressure and cholesterol under control. When you have prediabetes, you are more likely to get heart disease than someone with normal blood sugar levels. High cholesterol also increases your risk for type 2 diabetes.³ So it's important to keep your blood pressure and cholesterol under control. For help, see:

  Therapeutic Lifestyle Changes (TLC) for high cholesterol.

  High Blood Pressure: Checking Your Blood Pressure at Home.

For more tips, see the Home Treatment section of this topic.

Small steps to prevention

The Canadian Diabetes Association's "Verve" guide shows ways you can make small changes to your lifestyle that can have a big impact on preventing prediabetes and type 2 diabetes.

These changes include:

• Setting weight-loss goals.
• Adding exercise to your life.
• Tracking your progress.

For more information, search for Verve on the Canadian Diabetes Association's Web site at www.diabetes.ca.

Setting A Goal To Prevent Type 2 Diabetes

Prediabetes is a warning sign that you are at risk for type 2 diabetes. But you can make the healthy changes needed to prevent it.

Losing weight, getting active, eating better, and quitting smoking are all important changes you can make for your health. But you don't have to do them all at once. Just pick one to start, such as losing weight. It's one of the best things you can do to prevent prediabetes or to stop it from turning into type 2 diabetes. Three steps can help you get started.

1. Know your reason. Before you set a goal, think about why you want to make a change. If your reason comes from you—and not from someone else—it will be easier for you to make a healthy change for good.

Maybe you want to avoid the hassles that come with type 2 diabetes, such as taking insulin or testing blood sugar. Or maybe you are worried about the health problems diabetes brings. You might simply want to enjoy your life and have more energy. Your reason for wanting to change is important.

2. Set long-term and short-term goals. Start by setting a big, or long-term, goal. Maybe you want to lose 10% of your body weight to reduce your risk of type 2 diabetes. If you weigh 100 kilograms, that means losing 10 kilograms. Break down your big goal into smaller, short-term goals. These are the steps you'll take to reach your big goal.

Do what works best for you. It's important to set goals you can reach. For example:

• Week 1: Set a goal to walk for 15 minutes, 5 days a week.
• Week 2: Continue to walk for 15 minutes, 5 days a week. And this week, when you reach for a snack, make it carrots or celery sticks instead of potato chips or crackers.
• Week 3: Keep up your walking program and eating healthy snacks. Gradually increase walking to 30 minutes for at least 5 days each week. Pay attention to your hunger levels when you eat meals. Stop eating when you feel full.

For help, see:

Fitness: Adding More Activity to Your Life.

Fitness: Walking for Wellness.

Healthy Eating: Starting a Plan for Change.

Healthy Eating: Recognizing Your Hunger Signals.

3. Prepare for slip-ups and barriers. Plan for setbacks. Use a personal action plan (What is a PDF document?) to write down your goals, any possible barriers, and your ideas for getting past them. By thinking about these barriers now, you can plan ahead for how to deal with them if they happen.

For help, see:

Healthy Eating: Overcoming Barriers to Change.

Quitting Smoking: Preventing Slips and Relapses.

Tips for staying on track

• Get support. Tell family and friends your reasons for wanting to change. Tell them that their encouragement makes a big difference to you in your goal to prevent type 2 diabetes. Your doctor or a professional counsellor can also provide support.
• Pat yourself on the back. Don't forget to give yourself some positive feedback. If you slip up, don't waste energy feeling bad about yourself. Instead, think about how much closer you are to reaching your goal than when you started.

Home Treatment

You play a major role in managing prediabetes and preventing it from turning into type 2 diabetes.² You can do this by:

• Watching your weight.
• Making healthy food choices.
• Being active.
• Not smoking.
• Controlling blood pressure and cholesterol levels.

Watch your weight

Losing 5% to 10% of your body weight may help you prevent or at least delay type 2 diabetes.² For example, if you weigh "100 kilograms, losing 5 to 10 kilograms can reduce your risk.

Losing weight can also lower insulin resistance. The more you lose, the more you benefit, as long as you do it in a healthy way.²

Losing weight can be hard, but you can do it. The easiest way to start is by cutting calories and becoming more active. For help, see the topic Weight Management and:

Healthy Eating: Recognizing Your Hunger Signals.

Healthy Eating: Getting Support When Changing Your Eating Habits.

Fitness: Adding More Activity to Your Life.

Make healthy food choices

Planning meals to manage prediabetes can often mean looking at food in a new way. There are several easy ways to make healthy changes to the way you eat. One way to start is by eating foods that are low in saturated fat and high in fibre. Or you might try cutting down on foods that are high in calories but low in nutrition, such as soda.

A registered dietitian can help you make a meal plan that fits your lifestyle.

For help, see the topic Healthy Eating and:

Healthy Eating: Cutting Unhealthy Fats From Your Diet.

Healthy Eating: Changing Your Eating Habits.

Healthy Eating: Staying With Your Eating Plan.

Get active

The more active you are, the more sugar (glucose) your body uses for energy. This keeps the sugar from building up in your blood. Being active also:

• Helps your body respond better to insulin and lowers your risk of getting type 2 diabetes.
• Helps you reach and stay at a healthy weight and reduce belly fat.
• Lowers cholesterol.
• Raises high-density lipoprotein (HDL), or "good," cholesterol.
• Lowers high blood pressure.

Don't worry. You don't have to sign up for a gym membership or train for a marathon to get the activity you need to manage prediabetes. Even everyday activities can help.

Try to do moderate to vigorous activity for at least 2½ hours a week.⁵

Any type of activity helps, including:

• Walking, jogging, swimming, or biking.
• Household work, such as vacuuming or gardening.

Moderate activity is safe for most people, but it's always a good idea to talk to your doctor before you start an exercise program.

For help, see the topic Fitness and:

Quick Tips: Getting Active At Home.

Fitness: Walking for Wellness.

One Man's Story: Jerry, 54 "Taking care of yourself can make a huge difference in your health. It's possible that I may still get type 2 diabetes at some point. But I know that even if I do, I'm way ahead in terms of managing it. So don't sit around and wait for it to happen. Get up and move!"—Jerry Read more about Jerry.

If you smoke, quit

Quitting smoking can help you reduce your risk of getting type 2 diabetes and other health problems. Quitting can also reduce your risk of heart attack and stroke. For help, see:

Quitting Smoking: Getting Support.

Control blood pressure and cholesterol

When you have prediabetes, you are more likely to get heart disease than someone who has normal blood sugar levels. High cholesterol also increases your risk for type 2 diabetes.⁷ So it's important to keep your blood pressure and cholesterol under control. For help, see:

Therapeutic Lifestyle Changes (TLC) for high cholesterol.

High Blood Pressure: Checking Your Blood Pressure at Home.

Medications

Most people who have prediabetes get better results by making lifestyle changes than by taking diabetes medicine.⁸ You can make these changes too:

• Watch your weight.
• Make healthy food choices.
• Be active.

Your doctor may prescribe:

• Metformin (Glucophage) . If you need medicine, your doctor is most likely to prescribe this one. Metformin reduces how much glucose the liver makes. It can also lower insulin resistance.
• Pioglitazone or rosiglitazone (Actos or Avandia). Your doctor may have you take one of these medicines instead of metformin to lower your insulin resistance.

Talk with your doctor to find out if you need medicine in addition to lifestyle changes to lower your insulin resistance.

Other Treatment

Avoid products that promise a cure for prediabetes. The best way to treat prediabetes is to:

• Watch your weight.
• Make healthy food choices.
• Be active.

If you have questions about a diet or product for diabetes, check with your local Canadian Diabetes Association office. Or talk with your doctor or a diabetes educator.