UNC Health Care
graphic of blood sugar test

You Have Prediabetes. Now What?

Prediabetes is a condition in which blood glucose concentrations—often called blood sugar—are higher than normal but don’t yet meet the criteria for diabetes. However, untreated prediabetes often leads to full-fledged diabetes in five years or less.

The Centers for Disease Control and Prevention estimates that 84.1 million American adults have prediabetes, representing about 34 percent of the population. Nearly 90 percent of people with prediabetes don’t even know they have it.

But having prediabetes doesn’t destine you for diabetes. With early detection and preventive measures, you can stop prediabetes from becoming the real thing.

Understanding Diabetes and Prediabetes

Diabetes is a condition in which the body’s blood glucose, or blood sugar, is too high and isn’t being used in the cells for energy as intended. Insulin, a hormone created by the pancreas, is supposed to get glucose into your cells, but sometimes the body doesn’t make enough insulin or doesn’t use insulin well.

Over time, having too much glucose in your blood can cause serious health problems, including heart disease and stroke, nerve damage, kidney disease and vision disorders.

There are different types of diabetes, including type 1, in which the body does not make insulin, and type 2, in which the body doesn’t make enough insulin or use insulin well. There is also gestational diabetes, which happens in some women during pregnancy.

Prediabetes is a precursor to type 2 diabetes.

Risk Factors for Prediabetes

The risk factors for diabetes and prediabetes are the same, says UNC Health Care endocrinologist Gauri Dhir, MD.

“Obesity and diabetes go hand in hand,” Dr. Dhir says. “As rates of obesity increase, so do rates of diabetes.” Nearly 40 percent of U.S. adults and 18.5 percent of youth ages 2 to 19 are obese. There is strong and consistent evidence that managing obesity can delay the progression of prediabetes to diabetes.

Other risk factors include:

  • Diet and physical inactivity: Inactive people are more likely to be overweight and have more body fat, making them more susceptible to diabetes. Furthermore, if you are active, you use up glucose as energy, which helps keep your glucose levels down.
  • Family history: “Genetics play a role,” Dr. Dhir says. “An individual is more at risk if a sibling or parent has diabetes.”
  • Age: You are at higher risk if you are 45 and older.
  • Race: African-Americans, Asian-Americans, Native Americans and Hispanics have an increased risk of diabetes.

Signs of Prediabetes

There are no clear warning signs or symptoms of prediabetes.

With so many people not knowing they have it, prediabetes is “a growing public health challenge today,” Dr. Dhir says. “If you are overweight or obese, have a family history of diabetes, you should get checked.”

A simple blood test will determine if you have prediabetes. Your doctor may do one of the following:

  • A1C: The A1C test measures average blood glucose levels for the past two to three months. With this test, you don’t have to fast beforehand.The A1C test result is reported as a percentage. A normal A1C level is below 5.7 percent. Prediabetic is 5.7 to 6.4 percent, and diabetic is 6.5 percent or higher.
  • Fasting plasma glucose (FPG): This test determines your fasting blood glucose levels. You cannot eat or drink anything except water for eight hours before having your blood drawn, so this test is usually scheduled early in the morning.

A fasting blood sugar level of less than 100 mg/dl (milligrams per deciliter) is considered normal. If your fasting blood sugar level is 100 to 125 mg/dl, you are considered prediabetic. If it is 126 mg/dl or greater, you will be diagnosed with diabetes.

  • Oral glucose tolerance test (OGTT): This test checks your blood glucose before and two hours after drinking a special high-sugar beverage. This provides the physician with information about how your body processes glucose.

A blood sugar level of less than 140 mg/dl is considered normal. Levels of 140 to 199 mg/dl are considered prediabetic, and diabetes is diagnosed at 200 mg/dl or higher.

Preventing Prediabetes from Becoming Diabetes

The best way to prevent diabetes if you already have prediabetes is to focus on lifestyle changes, Dr. Dhir says.

“Eating healthy foods, incorporating physical activity in your daily routine and maintaining a healthy weight can help bring your blood sugar level back to normal,” Dr. Dhir says. “You should try to exercise at moderate intensity at least 30 minutes a day, five times per week.”

Diet is critical, too. “Try focusing on increasing nonstarchy vegetables such as carrots, lettuce, onions and peppers, eating quality lean protein and cutting back on carbs and processed foods,” Dr. Dhir says. “And as difficult as it may be, cut down on the sugary drinks, candy and desserts.”

In addition to lifestyle changes, some drugs can be used to combat and reverse prediabetes, Dr. Dhir adds. There are several trials underway using diabetic medications such as metformin and acarbose; some of these drugs have been shown to reduce the risk of progression of prediabetes to diabetes. Drugs used to treat obesity, including liraglutide and orlistat, have also been shown to help.

But the best route to take is still diet and exercise, experts say. In research, lifestyle changes have outperformed drugs in reducing risk.

These changes can be difficult, so it’s important to work with a doctor to come up with a plan you can sustain long term. With the right adjustments, you can reverse prediabetes and avoid diabetes altogether.


 If you think you may be at risk for prediabetes or diabetes, talk to your doctor. If you need a doctor, find one near you.