Prediabetes: Warning! Warning!

Unlike many medical conditions, most people that develop type 2 diabetes will have some precursor indicators that they are at risk for developing the disease. However, the good new for people diagnosed with prediabetes is that there are lifestyle changes, including weight loss and changes in diet, which can be used to reduce the risk of developing full type 2 diabetes. Prediabetes symptoms are only associated with type 2 diabetes, never with type 1 diabetes.

In the past prediabetes has been recognized by two different names. These two names were Impaired Glucose Tolerance (IGT) or Impaired Fasting Glucose (IFG). All names, including the more commonly accepted term prediabetes, indicate the same health risk, which is an elevate blood sugar level that is above normal but not at the level required for diagnosis of type 2 diabetes.

Prevalence of Prediabetes

According to the American Diabetes Association it is estimated that in 2000 there were approximately 12 million adults in the United States between the ages of 45 and 74 that were at risk for developing type 2 diabetes. This was further refined in the study by indicating that 17.1% had IGT and 11.9% had IFG, 22.6% had prediabetes and 5.6% had both IGT and IFG.  Within the study IGT was defined as 2-h glucose 140–199 mg/dl and IFG as fasting glucose 110–125 mg/dl. The conclusion of the report indicated that this number is significantly higher if the age range is increased to include adults between the ages of 25 to 44 years and those over the age of 75. 1

In another study in the United States it was determined that over 40% of the adult population in the country at or over the age of 20 had hyperglycemic conditions which led to higher rates of the diagnosis of diabetes. This study used the fasting and 2-hour oral glucose tolerance test as a standardized test. The study also found that the prevalence of both prediabetes and diagnosed diabetes varied based on ethnicity with non-Hispanic blacks and Mexican Americans diagnosed at rates double that of non-Hispanic whites. 2

Symptoms of Prediabetes

The vast majority of individuals with prediabetes will have no specific physical symptoms. Some people may develop a condition known as acanthosis nigricans, which is the most commonly noted symptom of prediabetes. This is a darkened area of the skin that is most common around the joint areas of the body including the knuckles, elbows, neck, armpits and knees.

Other symptoms that occur are often not attributed to the development of prediabetes and may, in fact, be assumed by the individual to be normal parts of aging. These overlooked symptoms can include: 3

  • Altered sensations in the extremities – numbness, tingling, cramping
  • Changes in urination – more frequent and larger volume
  • Vision problems – dry eyes, eye irritations, tearing, poor eyesight
  • Fatigue and energy – extreme exhaustion, faintness, dizziness, lack of strength, increased need for sleep
  • Muscle and joint problems – pains, stiffness, lack of range of motion
  • Digestive problems – gas, constipation, diarrhea, dry mouth, thirst

As prediabetes blood sugar levels increase, these symptoms become more pronounced and more evident, often contributing to the diagnosis of type 2 diabetes.

Another common concurrent condition seen in people with prediabetes and diagnosed or undiagnosed type 2 diabetes is depression. One possible reason why depression is often seen with diabetes or prediabetes is that it’s a by-product of the symptoms just listed. Patients also develop an awareness of the greater risk of developing cardiovascular disease. Symptoms impact the quality of life for the individual. Women have a slightly higher rate of depression, approximately 19.7% compared to 15% for men. 4

Risk Factors For Developing Prediabetes

The risk factors for developing prediabetes are the same as those for the development of type 2 diabetes. They include:

  • Body Mass Index (BMI) greater than 25
  • Individuals over the age of 45
  • History of gestational diabetes or having a child that weighed more than 9 pounds at birth
  • Family history of diabetes
  • High blood pressure
  • History of insomnia or sleeping less that 5.5 hours per night
  • Sedentary and inactive lifestyle
  • HDL levels below 40 mg/dL or triglyceride levels of more than 150 mg/dL
  • African-American, Hispanic, Pacific Islander, Asian or Native American
  • History of polycystic ovary syndrome in women

The more risk factors that you have the greater the risk of developing prediabetes and then type 2 diabetes. Modifying diet, exercise and overall health can reduce your risk or reverse the progression of the condition, allowing you to live a diabetes free life.

Diagnosis of Prediabetes

The most common way that prediabetes is diagnosed is through a blood glucose screening. This typically occurs at an annual medical check-up if there are risk factors present. There are several tests possible. Depending on your current health conditions and the testing most commonly used by your doctor the following may be used:

  • Impaired Fasting Glucose (IFG) – patients will be required to fast for at least eight hours, typically overnight, then a blood sample is collected. The blood sugar level determined from the sample will indicate of prediabetes is present. Normal readings are 100 milligrams per deciliter (mg/dL) or lower. Readings between 100 to 125 mg/dL indicate prediabetes.
  • Impaired Glucose Tolerance (IGT) – similar to the IFG test the patient will fast overnight and then submit a blood sample. He or she will then drink a sugar rich drink and, in two hours, blood sugar levels are taken again. Normal range in this test is 140 mg/dL and prediabetes is 140-199 mg/dL.
  • Glycated hemoglobin test (A1C) – considered the most comprehensive blood test this allows the medical team to review the average blood sugar levels in your body over the last two to three months. This is done by measuring the blood sugar that is attached to the hemoglobin in the blood. Prediabetes is indicated by levels of 5.7 to 6.4 is considered to be prediabetes.
  • Fasting Blood Glucose – this relatively simple test can be done after fasting for at least 8 hours. If the glucose level is between 100-125 mg/dL, you have prediabetes.

Testing is usually done annually for those with risk factors and every three years for those with normal readings, healthy body weight, an active lifestyle and few risk factors.


1 Benjamin, S. M., Valdez, R., & Geiss, L. S. (2003). Estimated Number of Adults With Prediabetes in the U.S. in 2000. Diabetes Care , 645-649.

2 Cowie, C. C., Rust, K. F., Ford, E. S., et al. (2009). Full Accounting of Diabetes and Pre-Diabetes in the U.S. Population in 1988–1994 and 2005–2006. Diabetes Care , 287-294.

3 Andersson, S., Ekman, I., Lindblad, U., & Friberg, F. (2011). Perceived Symptoms in People Living With Impaired Glucose Tolerance. Nursing Research and Practice .

4 Andriaanse, M. C., Dekker, J. M., Heine, R. J., et al. (2008). Symptoms of depression in people with impaired glucose metabolism or Type 2 diabetes mellitus: The Hoorn Study. Diabetic Medicine , 843-849.

This article was originally published July 12, 2012 and last revision and update of it was 9/10/2015.