Diabetes and Lipid Clinic of Alaska



About Pre-Diabetes

Pre-diabetes exists when a person has glucose (blood sugar) levels higher than normal but not high enough to be diagnosed as diabetes. It often, but not always, escalates to type 2 diabetes, which accounts for an estimated 90 to 95 percent of cases of diabetes.

In the past, mildly elevated levels of glucose were often ignored. Today, glucose levels slightly above the normal range are a warning sign for an individual to take prompt action to prevent type 2 diabetes.

In the United States and worldwide, there has been a steady increase in the number of people diagnosed with diabetes. According to the U.S. Centers for Disease Control and Prevention (CDC), the number of new cases of Americans diagnosed with diabetes increased by 54 percent between 1997 and 2004.

The CDC estimated in 2005 that, based on statistics from 1988 to 1994, 41 million Americans ages 40 to 74 had pre-diabetes – 40 percent of that total population. About 2 million American adolescents have pre-diabetes, according to a 2006 federal study using data from a 1999-2000 national survey. With rates of obesity soaring in recent years, the number of people with pre-diabetes is now likely higher.

Given these facts, scientists are researching ways to earlier identify people at risk for diabetes. Unlike type 1 diabetes, it is believed that that with early identification, type 2 diabetes may be delayed or even prevented. A diagnosis of pre-diabetes has emerged as a condition for predicting individuals at risk for type 2 diabetes.

Pre-diabetes can be diagnosed by a physician using standard glucose tests. A fasting blood glucose test (FPG) or an oral glucose tolerance test (OGTT) can be used to identify the condition. These tests measure the level of glucose in the blood. If the level of glucose is found to be within a certain elevated range, pre-diabetes is diagnosed. The range, in milliliters per deciliter of blood, is 100 to 125 mg/dL for a fasting blood glucose test and 140 to 199 mg/dL for an oral glucose challenge test.

Even glucose at the high range of normal may be a concern. A recently completed 12-year Israeli study of more than 13,000 troops found that those with fasting glucose of 95 to 99 mg/dL were several times more likely than those with lower glucose to become diabetic.

Studies conducted by the U.S. Department of Health and Human Services indicate that individuals with pre-diabetes will likely develop type 2 diabetes within 10 years unless changes are made to their lifestyle. In addition, women diagnosed with pre-diabetes are at a high risk of developing gestational diabetes during pregnancy.

Treating pre-diabetes helps prevent the onset to type 2 diabetes and is important for other reasons as well. Research has shown that medical complications linked to diabetes may actually start in the pre-diabetes stage. The heart, blood vessels, kidneys and eyes may be damaged during the pre-diabetes condition. Treatment and prevention in the prediabetic state may slow down the damage of vital organs and body systems.

Recent research shows that:

  • Almost 8 percent of the (pre-diabetic) participants in the Diabetes Prevention Program developed early-stage diabetic retinopathy.
  • People with pre-diabetes are more likely to develop chronic kidney disease than those with normal glucose, mainly because of cardiovascular risk factors such as high blood pressure.
  • Pre-diabetes increases the risk of heart disease, according to a nine-year study of more than 28,000 patients.
  • The type of nerve damage associated with diabetes (diabetic neuropathy) can be present in people with pre-diabetes.
  • Pre-diabetic women have increased risk of urinary incontinence, which can be improved with weight loss.

A condition related to pre-diabetes that also often develops before type 2 diabetes is impairment in the body’s ability to use insulin to process glucose for energy. For more information, see Insulin Resistance

Risk factors for the development of pre diabetes

As with type 2 diabetes, there is no single cause for pre-diabetes. The same risk factors for type 2 diabetes are present for pre-diabetes. People are at higher risk for pre-diabetes if they have one or more of the following risk factors:

  • Age over 45
  • Family history of diabetes
  • Overweight or obesity
  • High blood pressure
  • Low HDL (good) and high LDL (bad) cholesterol
  • Belonging to certain minority groups
  • History of gestational diabetes or having given birth to a baby larger than 9 pounds (macrosomia)
  • History of polycystic ovarian syndrome (PCOS)

Symptoms and diagnosis

There are usually no symptoms of pre-diabetes. Since the blood glucose level is not as high as with type 2 diabetes, there may be no indication of a problem. For this reason, the American Diabetes Association recommends that anyone 45 years or older have a glucose test. Glucose screening is particularly important if the individual is overweight, obese or has a family history of diabetes.

In addition, overweight individuals under the age of 45 may be screened if they have any of the other risk factors for diabetes. Children and adolescents who are at risk should be screened every 2 years after the age of 10, or at the onset of puberty if it occurs at a younger age.

There are two standard tests used for diagnosing pre-diabetes. They are administered differently but both provide results that indicate high glucose (blood sugar) levels and pre-diabetes.

These tests, which can be administered in a physician’s office, are:

  • Fasting plasma glucose test (FPG). A sample of blood is taken from the vein after an individual has not had anything to eat or drink for eight to 10 hours. The blood is tested for the amount of glucose that is present in the
    sample. If the fasting glucose is between 100 and 125 milligrams per deciliter (mg/dL), the individual has pre diabetes. Higher than 126 is consistent with diabetes.
  • Oral glucose tolerance test (OGTT). This test requires an individual to drink 8 ounces of a glucose solution after fasting overnight. The glucose is measured before drinking the liquid, then every hour for a two– to three–hour period. If glucose levels rise to between 140 and 199 mg/dL, the individual has prediabetes.

Glucose Levels for Prediabetes and Diabetes
in milligrams per deciliter (mg/dL)






99 or lower

100 to 125

126 or higher


139 or lower

140 to 199

200 or higher

Both tests should be performed at different times to confirm a diagnosis of prediabetes. Once diagnosed with pre-diabetes, the person will be given a plan of treatment by their physician to help prevent type 2 diabetes.

Treatment and prevention for pre-diabetes

A panel of physicians and diabetes experts from the Centers for Disease Control and Prevention (CDC) and the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) concluded that treatment for pre-diabetes is crucial for several reasons. These reasons include:

  • Damage to vital organs and systems in the body from high glucose (blood sugar) levels can begin in the pre-diabetes stage.
  • Having glucose levels in the pre-diabetes range places a person at a 50 percent higher risk for having a heart attack or stroke.
  • With modest lifestyle changes, the development of type 2 diabetes can be delayed or prevented.
  • Lifestyle changes can return elevated glucose levels to the normal range.

The U.S. Department of Health and Human Services (HHS) conducted a large prevention study of pre-diabetic people at high risk for diabetes. In the Diabetes Prevention Program, lifestyle changes reduced the development of type 2 diabetes by 58 percent over three years. Based on this study, HHS recommended the following changes in lifestyle:

  • Weight loss. Modest weight loss in overweight individuals has been shown to prevent or delay type 2 diabetes. The recommended goal is 5 to 10 percent of the person’s body weight. Reduced weight may decrease other risks such as high blood pressure and cholesterol as well.
  • Physical activity. Modest exercise or other physical activity decreases the risk of getting type 2 diabetes. Sedentary lifestyles do not help pre-diabetic patients. Modest physical activity of 30 minutes per day is recommended for reducing risk. It can be activity as simple as walking and can be split into several sessions per day. The total amount of exercise recommended is a minimum of 150 minutes per week. Exercise improves cardiovascular
    function and circulation and can improve blood pressure and cholesterol levels.

Medications including metformin were also examined in the Diabetes Prevention Program. These drugs work to sensitize the body to the actions of insulin. The chance of preventing type 2 diabetes with medication varied according to the age and weight of the individual and the type of medication. Metformin reduced the risk of developing type 2 diabetes by 31 percent over a three–year period. The study concluded that drug therapy, though effective, appeared to be less beneficial than the 58 percent reduction through lifestyle changes for the prevention of type 2 diabetes.

Making improvements in weight and physical activity is the best way to prevent prediabetes from progressing to type 2 diabetes. Other lifestyle changes that may be included in a treatment plan for pre-diabetes are:

  1. Eat a healthy diet that is low in fats and sweets, and high in fiber
  2. Stop smoking
  3. Avoid the use of alcohol
  4. Treat high blood pressure and unhealthy cholesterol levels

Modest consumption of alcohol can decrease an individual’s risk of diabetes, according to the Harvard School of Public Health, but heavier consumption is harmful.
As with type 2 diabetes, a physician must recommend any changes and prescribe a plan of treatment specific to the patient. Once the plan is in place, it is important the individual closely follow the treatment to maximize the chances for a healthy life without diabetes

For more information, please consult with the medical professionals at Diabetes and Lipid Clinic of Alaska.

The information on this Web page is provided for educational purposes. You understand and agree that this information is not intended to be, and should not be used as, a substitute for medical treatment by a health care professional. You agree that Diabetes and Lipid Clinic of Alaska is not making a diagnosis of your condition or a recommendation about the course of treatment for your particular circumstances through the use of this Web page. You agree to be solely responsible for your use of information contained on this Web page.

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