When a person has prediabetes, their blood glucose levels are consistently high but not yet high enough to develop into type 2 diabetes.
Prediabetes is a widespread condition in the United States. Around 33.9 percent of people over 18 years of age and nearly 50 percent of people aged 65 years and older have prediabetes, according to the Centers for Disease Control and Prevention (CDC).
Getting enough exercise, eating a wholesome diet, and maintaining a healthful weight can reverse prediabetes and prevent the development of type 2 diabetes.
In this article, we look at prediabetes, ways to test for it, and how to reverse the condition.
Prediabetes is when someone has consistently high blood sugar levels that have not yet reached the stage of type 2 diabetes.
When a person has prediabetes, their body cannot use insulin effectively. Insulin is the hormone responsible for transporting sugar from the bloodstream to the cells to use for energy.
Sometimes, the inability to use insulin correctly results in the cells not getting enough sugar. As a consequence, too much sugar remains in the bloodstream.
High blood sugar levels can cause serious health complications, especially damage to the blood vessels, heart, and kidney.
According to the CDC, more than 84 million adults in the U.S. have prediabetes, but many do not know they have the condition, as it is completely symptomless.
By the time most people experience symptoms, the condition has usually progressed to type 2 diabetes.
However, glucose testing should begin earlier for people who have risk factors for diabetes, such as being overweight or having a family history of diabetes.
Several blood sugar tests can confirm a diagnosis of prediabetes. Doctors repeat tests two or three times before confirming a diagnosis.
Glycated hemoglobin test
Healthcare professionals call the glycated hemoglobin test the A1C test. They use it to check an individual's average levels of blood sugar over the previous 3 months.
An A1C blood test score of between 5.7 and 6.4 percent means an individual is likely to have prediabetes.
Some conditions, such as pregnancy, can impact on a person's blood sugar levels and may interfere with A1C results.
In addition, results for some people may show inaccuracies in A1C testing. These include results from individuals of certain ethnicities with a genetic sickle cell trait, including people of African, Mediterranean, or Southeast Asian descent.
These inaccuracies can lead to a misdiagnosis of the disease or poor management of blood sugar.
Fasting blood glucose test
The fasting blood glucose test (FBGT) measures sugar levels at the time of the measurement. Doctors consider a result of 100—125 milligrams per deciliter (mg/dl) to be a sign of prediabetes.
Those people taking the FBGT cannot eat or drink for at least 8 hours before giving a blood sample. Many arrange the test for early morning, as most people will already have fasted overnight.
Oral glucose tolerance test
The oral glucose tolerance test (OGTT) also requires 8 hours of fasting. Typically, blood sugar levels will then be checked before and 2 hours after drinking a glucose drink.
Other protocols include testing blood sugar levels every 30–60 minutes after consuming the glucose drink.
Doctors consider a 2-hour value of 140–199 mg/dl to be a sign of impaired glucose tolerance. Prediabetes produces this effect on the blood.
Doctors often use the OGTT to help diagnose people who should not undergo the A1C test, such as women who may have gestational diabetes or those with blood conditions.
Prediabetes testing in children
According to the ADA, in 2012, the number of adolescents aged 12–19 years with prediabetes had increased from 9 percent of this age group to 23 percent.
The ADA recommend annual diabetes screenings for children who are overweight or have a combination of risk factors for prediabetes. Typically, medical professionals will interpret the test results for children in the same way as those for adults.
The risk factors for prediabetes and diabetes in children include:
- Being overweight: Children who are obese or have high levels of fat around the midriff have a higher risk of prediabetes than children who are not.
- Age: Most diagnoses of type 2 diabetes in children occur during their early teens.
- Family: Children who have family members with type 2 diabetes or a mother who had gestational diabetes are more likely to struggle with blood sugar control.
- Race or ethnicity: Children of African American, Native American, and Hispanic descent are more likely to develop type 2 diabetes in comparison to other races and ethnicities.
Once a doctor diagnoses prediabetes, people must undergo regular testing. This provides a better understanding of blood sugar changes and the progression of the condition.
Keeping an eye on blood sugar levels over time also helps a person monitor the impact of any changes they make to their lifestyle or diet. It is possible to reverse prediabetes with the correct lifestyle measures.
People with prediabetes should have blood glucose tests at least once a year or more often, depending on their risk factors.
Many factors can contribute to the development of prediabetes.
Increasingly, research has identified links between family history and prediabetes. However, a sedentary lifestyle and excess belly fat are among the most common and influential causes of prediabetes and type 2 diabetes.
Risk factors for prediabetes and type 2 diabetes include:
Being overweight or obese: The increased presence of fatty tissue reduces the sensitivity of the cells to glucose.
- Age: Prediabetes can develop at any age, but health experts believe the risk rises after 45 years of age. This may be due to inactivity, poor diet, and a loss of muscle mass, which typically declines with age.
- Diet: Regularly consuming excess carbohydrates, especially sweetened foods or drinks, can impair insulin sensitivity over time. Diets that are high in red or processed meats also have links to the development of prediabetes.
- Sleep patterns: According to this 2018 study, people with obstructive sleep apnea have an increased risk of developing prediabetes.
- Family history: Having an immediate relative with type 2 diabetes significantly increases the risk of someone developing the condition.
- Stress: Research from 2018 into males in the workplace found that people who experience long-term stress may face a higher than normal risk of diabetes. During periods of stress, the body releases the hormone cortisol into the bloodstream, raising blood glucose levels.
- Gestational diabetes: Women who give birth to infants weighing 9 pounds or more may have a higher risk of prediabetes. Those who develop gestational diabetes during pregnancy and their children are also at a higher risk of developing the condition.
- Polycystic ovary syndrome (PCOS): Women with PCOS are more susceptible to insulin resistance, which can lead to prediabetes or type 2 diabetes. Women with type 1 diabetes have a higher risk of PCOS than women who do not have the condition.
- Ethnicity: The risk of developing prediabetes tends to be higher for African Americans, Native Americans, Hispanics, Pacific Islanders, and Asian Americans. The reason remains unclear.
- Metabolic syndrome: A combination of the impact of obesity, high blood pressure, high levels of triglycerides, or "bad" fats, and low levels of high-density lipoprotein, HDL or "good" fats, can increase insulin resistance over time. Metabolic syndrome is the presence of three or more conditions that influence a person's metabolism.
Exercise and diet can help an individual reverse prediabetes, although not every recommendation works for all people.
Some people use herbs and supplements to manage their diet. However, the National Institute of Diabetes and Digestive and Kidney Disorders (NIDDK) advise that no research supports the use of specific spices, herbs, vitamins, and minerals to treat diabetes.
Healthful lifestyle changes can reduce the chances of developing type 2 diabetes. These changes include:
- Losing weight: Losing roughly 7 percent of total body weight, particularly reducing belly fat, may reduce the risk of developing type 2 diabetes by 58 percent.
- Undertaking moderate, consistent activity: People with diabetes should attempt 150 minutes of moderate exercise per week. Even if people are not feeling ready for an intensive workout, going for a walk or gardening can make a difference.
- Increasing muscle mass: Muscle burns calories at a higher rate than fat, so increasing muscle mass can contribute to achieving a healthy weight. This, in turn, may help to stabilize blood glucose levels.
- Increasing flexibility: Stretching is a form of exercise. Being flexible can also help reduce the impact of injuries and improve recovery, resulting in a more reliable exercise regimen.
- Reducing stress: As stress might be a risk factor for prediabetes, managing stress levels can help prevent the condition.
- Having a healthful diet: Diets that are high in fiber, lean proteins, and complex carbohydrates but low in simple sugars, help keep blood glucose levels stable.
- Sticking to a strict meal schedule: Eating smaller meals regularly throughout the day helps prevent spikes and dips in blood glucose levels. Be sure to eat at similar times each day and avoid snacking excessively between meals.
- Stopping smoking: Nicotine is a stimulant that raises blood glucose levels. Smoking can cause insulin resistance and is a risk factor for diabetes.
- Avoiding excess sugars: Foods and drinks with added sugars can cause extreme changes in blood glucose and contribute to weight gain.
- Sticking to moderate coffee intake: Caffeine is another stimulant that increases blood glucose levels. However, some studies have linked coffee to increasing insulin sensitivity.
- Getting enough sleep: One 2015 study suggests that people who have low sleep quality also face a higher risk of prediabetes.
People with prediabetes risk factors or high blood glucose levels may need to monitor their levels at home and take medication to reduce blood glucose.
A doctor may prescribe some people with prediabetes medications, such as metformin, to manage their symptoms.
Signs that prediabetes has progressed to type 2 diabetes include:
- increased or unrelenting thirst
- fatigue or feeling weak
- feeling faint or dizzy
- blurred vision
Anyone who experiences these symptoms may want to see their doctor for a medical opinion.
People who have a diagnosis of prediabetes should not be alarmed. Instead, they can use this as an opportunity to focus on diet and an exercise regimen to potentially reverse the progression of the disease.
Are all exercises safe for reversing prediabetes?
There is no additional risk to exercise because of prediabetes. However, with or without prediabetes or diabetes, you should talk to your doctor about any health concerns before beginning a new exercise regimen.Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.