All about borderline diabetes (prediabetes)

All about borderline diabetes (prediabetes)

An individual with borderline diabetes, or prediabetes, has levels of blood sugar that are higher than normal but not yet high enough for a type 2 diagnosis.

Borderline diabetes is a condition which can result in type 2 diabetes. An approximate 10 to 23 percent of people with borderline diabetes will begin to develop type 2 diabetes within 5 years, according to the American Diabetes Association.

Physicians may also refer to borderline diabetes as:

  • insulin resistance
  • impaired glucose tolerance
  • impaired fasting glucose

This article examines how to recognize prediabetes risk factors, how to manage the condition and how to prevent Type 2 diabetes from developing.


Prediabetes does not produce clear symptoms, so regular checks are important for people who are at risk.

Prediabetes does not have clear symptoms. Some people may not be aware that they have it until:

  • a doctor tests blood glucose and blood pressure levels
  • prediabetes has progressed to type 2 diabetes
  • a complication occurs, such as a heart attack

If a person’s blood sugar level remains high, certain signs of type 2 diabetes may begin to develop. Symptoms include increased urination and thirst.

Most people won’t know that they have prediabetes until they get the tests.

Causes and risk factors

According to the National Diabetes and Digestive and Kidney Disease Institute (NIDDK), a range of other conditions may increase prediabetes risk including:

Other risk factors include:

  • not getting enough exercise
  • having a family history of type 2 diabetes.

According to the American Heart Association, the following lifestyle factors may also be a risk for prediabetes in some people:

  • raised stress levels
  • smoking
  • drinking too much alcohol

Regularly consuming high-sugar drinks may also increase the risk.

Sugary drinks can contribute to the development of diabetes.
Sugary drinks can contribute to the development of diabetes.

One 2017 review found that people who drink sugar beverages regularly face an increased risk of metabolic diseases, such as high blood pressure and high blood glucose and fats.

Such metabolic conditions may result in prediabetes and diabetes.

People who lead an inactive lifestyle are at higher risk of taking in too many calories without exercising to consume them.

Other individuals at risk of developing prediabetes include those with polycystic ovary syndrome ( PCOS) and others who have had prior instances of high levels of blood sugar.

Anyone with any of these risk factors can take advantage of a prediabetes screening to determine if they have the condition.


A doctor typically diagnoses prediabetes with a blood test, specifically a test for glucose tolerance. A glucose tolerance test measures how fast the body can process blood sugar in a 2-hour period.

Other tests include measuring blood sugar levels after an individual has not eaten for a given period of time. This is called a fasting blood test.

The doctor can use an A1C test, too. It means calculating 2–3 months of daily blood sugar levels. For this test , people do not need to swiftly take or take any different liquids or medications and it gives accurate results.

A doctor can diagnose prediabetes when test results indicate the following measurements, the American Diabetes Association suggests:

  • fasting blood sugar levels of 100–125 milligrams per deciliter (mg/dl)
  • glucose tolerance levels of 140–199 mg/dl
  • an A1C test result of 5.7–6.4 percent

A doctor will often re-test these levels to confirm that the readings are not due to one-off spikes in blood sugar.

Who should seek screening?

The NIDDK recommend that people with the following risk factors should undergo a prediabetes screening:

  • an age of 45 years or over
  • obesity or overweight, or a body mass index (BMI) over 25
  • a waist circumference larger than 40 inches in males or over 35 inches in females
  • a close relative with diabetes
  • a condition that increases insulin resistance, including PCOS, acanthosis nigricans, and nonalcoholic steatohepatitis
  • an ethnic background that places an individual at high risk of diabetes, including people who are African-American, Asian-American, Latino, Native American, or a Pacific Islander
  • a history of gestational diabetes, or diabetes as a result of pregnancy
  • having given birth to an infant weighing over 9 pounds
  • having a disease that harden the arteries
  • recent treatment with glucocorticoids or atypical antipsychotic medications

If a doctor identifies any of those risk factors, the person may be recommended to have a blood glucose screening.

If a person has certain risk factors, medical professionals suggest repeating screening tests every 1 to 3 years.

The NIDDK has an official resource to check diabetes risk. To take the test click here.

Anyone who is concerned that they may have borderline diabetes should visit the doctor for a proper diagnosis and test.


Prediabetes is reversible but often prevention is easier than treatment. Factors in lifestyle are the primary causes of prediabetes, and improvements in some aspects of life can dramatically reduce risk factors.

A healthy , nutritious diet that balances sugar intake and regular exercise can help to reverse diabetes on the borderline.

A man doing Sport with bicycle
An active lifestyle can help prevent or reverse prediabetes.

The American Diabetes Association states that changes in diet and nutrition should include the following:

  • improving intake of unprocessed high-fiber carbohydrates
  • increasing fruit and vegetable consumption
  • reducing saturated fat and processed meat intake.

Exercising is important as well. Exercise can help avoid or delay diabetes development according to a study in Diabetes Treatment.

Latest American guidelines recommend adults should:

  • have at least 150–300 minutes of moderate-intensity aerobic activity each week
  • do muscle-strengthening exercises at least twice a week, such as lifting weights or doing push-ups

Examples of moderate exercise include fast dance and brisk walking.

Regular exercise and a balanced diet not only help reduce the risk of diabetes progression, but also protect the heart from potential diseases.

Diabetes Prevention Program

The Diabetes Prevention Program (DPP) was a long term study aimed to identify practical steps to reduce the risk of diabetes and reverse prediabetes.

The people who participated in the DPP Lifestyle Change Program aimed at losing 7 percent of their body weight and sustaining this loss through dietary changes and exercise. After 3 years the program’s results showed:

  • a 58-percent drop in the risk of developing diabetes regardless of sex or ethnicity, compared with those who took a placebo
  • a 71-percent drop in risk people of developing type 2 diabetes among people aged over 60 years

For the duration of the study, all the people in the program received motivational advice on healthy diet and exercise, and attended “lifestyle change classes.”

Follow-ups were regularly held. People in the DPP Lifestyle Change Program continued to see a delay in the onset of diabetes after 15 years compared to people taking a medication called metformin, or placebo.

Anyone who developed diabetes received additional medical care during the study. Diet and exercise, however, remained significant in managing symptoms and reducing the risk of complications.

Monitoring borderline diabetes

Aside from changes in lifestyle, doctors may prescribe other measures to manage the risk of diabetes.

Medical management may include treatment of associated conditions like obesity and heart disease.

Prediabetes treatment also includes constant monitoring of the risk factors and daily blood sugar levels testing.

A person may reverse borderline diabetes if they are able to make and maintain the lifestyle changes required.


Borderline diabetes is the stage before type 2 diabetes develops. Blood sugar, blood pressure, and insulin resistance can begin to reach dangerous levels by this stage.

Prediabetes usually does not cause active symptoms and most people will not be aware that they have the condition until it becomes diabetes and begins to cause serious health problems.

Therefore, getting regular screening is essential for anyone at risk of developing diabetes. Risk factors include high circumference of BMI and waist, age over 45 years, or other cardiovascular diseases.

Prediabetes with a sustained exercise program and a balanced, low-sugar diet is often reversible.


Which foods should I eat if I have prediabetes?


Fat and fiber help to speed up the absorption and the what is called the food glycemic index (GI). Low-GI fruits and vegetables, such as whole-wheat stone-ground bread, rolled or steel-cut oatmeal, non-starchy vegetables and whole fruits are good choices.

The American Diabetes Association recommends choosing foods with a GI of 55 or less. This database can be used to find the GI of common foods. Deborah Weatherspoon, PhD, RN, CRNA

Answers represent our medical experts’ opinions. All material is purely informational and medical advice should not be considered.