Reviewed by: HU Medical Review Board | Last reviewed: October 2020. | Last updated: March 2021
If you have prediabetes, you have blood glucose (sugar) levels that are higher than normal, but not high enough to be diagnosed with diabetes. Prediabetes is very common – about 1 in 3 adults in the United States has prediabetes. Plus, about 90 percent of people with prediabetes do not even know they have it.1,2
If you have prediabetes, your risk of developing type 2 diabetes within 5 to 10 years is dramatically increased. Prediabetes also increases your risk of heart attack and stroke.1,2
Learning that you have prediabetes can be scary. However, there is a positive side to this discovery. Getting this news means you have caught a serious health condition in the early stages while it is developing. The earlier you take action to manage your elevated blood glucose, the better chance you will have at slowing down or even stopping the progression to type 2 diabetes.
There are a number of steps you can take to delay or even prevent the development of type 2 diabetes. Your doctor can help create a prediabetes health plan that will lower your risk, and you can also find help through different lifestyle changes.
Prediabetes: a growing problem
The number of people with prediabetes around the world is rapidly increasing. Some experts project that more than 470 million people will have prediabetes by 2030. These researchers also predict that up to 70 percent of people with prediabetes will end up developing type 2 diabetes.3
Information from the 2020 National Diabetes Statistics Report also shows that prediabetes is a growing problem in the United States. Based on statistics from 2018, the Centers for Disease Control and Prevention (CDC) found that 34.5 percent of Americans ages 18 and older had prediabetes, with the highest rate among adults between the ages of 45 and 64.4
What causes prediabetes?
Experts are not sure exactly what causes insulin resistance and prediabetes, but they believe that extra weight and lack of physical activity are major factors.1
In prediabetes, the body loses the ability to effectively use the insulin it makes. This is called insulin resistance. Insulin is a hormone that is created in the pancreas, and it works to move glucose (sugar) from the food you eat into your cells so it can be used for energy. Since your body cannot use insulin well, too much glucose stays in your blood.5
As prediabetes progresses to type 2 diabetes, your body becomes more and more insulin resistant. Eventually, your body stops making any insulin. This leads to high blood glucose levels that cause type 2 diabetes and can lead to serious health problems.5
A number of genetic and lifestyle factors increase a person’s risk of insulin resistance or prediabetes. These include:1
- Being overweight or obese
- Having an immediate family member with diabetes
- Being 45 or older
- Physical inactivity
- Health conditions like high blood pressure or high cholesterol
- A history of gestational diabetes
- A history or heart disease or stroke
- Having polycystic ovary syndrome (PCOS)
- Having metabolic syndrome (a mixture of high blood pressure, high cholesterol levels, and large waist size)
- Black, Alaska Native, American Indian, Asian American, Hispanic/Latino, Native Hawaiian, or Pacific Islander ethnicity
- Having hormonal disorders, like Cushing’s syndrome
- Sleep problems, especially sleep apnea
While you cannot change some risk factors, like your age, ethnicity, or family history, you can make lifestyle changes that can dramatically lower your risk of developing prediabetes or type 2 diabetes.5
What are the symptoms of prediabetes?
In most cases, prediabetes develops without any symptoms at all, which is 1 reason why it is such a dangerous health condition. You may feel fine physically, even while high blood glucose and related health problems, like high blood pressure and excess weight, are causing damage to your body. Most people discover that they have prediabetes when they are being screened or examined for some other reason, such as an annual physical or check-up.
Even if you do not have symptoms, it is important to be tested for prediabetes if you are overweight or obese and have 1 more other risk factors for diabetes. Once you reach age 45, you should start getting tested even if you do not have risk factors.1
How is prediabetes diagnosed?
Your doctor will use blood glucose testing to determine if you have prediabetes. There are a few different tests that can be used to diagnose prediabetes. Testing is easy and usually done in a doctor’s office or a lab.The most common tests to diagnose prediabetes include:1,6
- Fasting blood glucose test – This is the quickest and simplest test used to diagnose prediabetes. It measures the level of glucose (sugar) in your blood. You will need to fast (not eat or drink anything except water) for at least 8 hours before your test.
- Hemoglobin A1C test – This test is commonly used to diagnose prediabetes. The hemoglobin A1C test measures your average blood glucose (sugar) level over the past 3 months.
- Oral glucose tolerance test – This test checks your blood sugar level before and after you drink a sweet drink that contains glucose (sugar). It measures how your body responds to sugar.
The following test results mean you have prediabetes:6
- Fasting blood glucose test – 100 to 125 mg/dl
- Hemoglobin A1C test – 5.7 to 6.4 percent
- Oral glucose tolerance test – 140 to 199 mg/dl
If your test results show that your blood sugar level is high, your doctor may have you take another test on a different day to recheck your level and confirm your prediabetes diagnosis.6
How can prediabetes be reversed or prevented?
Losing weight and regular physical activity are the 2 most important things you can do to reverse or prevent prediabetes. Both of these things help your body better respond to insulin.1
Even small steps can dramatically reduce your risk. Regular physical activity means getting at least 30 minutes of brisk walking or a similar activity 5 days a week. Studies have shown that losing a modest amount of weight – 5 to 7 percent of your starting weight – is beneficial. For example, if your starting weight is 200 pounds, that is 10 to 14 pounds.1,2
If you smoke, you should also quit. The risk of developing type 2 diabetes is 30 to 40 percent higher for smokers than nonsmokers.7
To get started with these changes, ask your doctor if there is a National Diabetes Prevention Program (NDPP) offered in your community. The program, which is offered through the CDC, can help you lower your risk of developing type 2 diabetes by up to 58 percent, or 71 percent if you are over age 60. You can also search online to find an NDPP location near you.