Prediabetes is a state in which blood sugar levels are higher than normal but not high enough for a diagnosis of diabetes.
Prediabetes is also referred to as “impaired fasting glucose” or “impaired glucose tolerance,” depending on the blood test used to make the diagnosis.
The Centers for Disease Control and Prevention (CDC) estimates that one of every three adults in the United States — or 79 million Americans age 20 or older — had prediabetes in 2010.
And the majority of these people didn’t even know they had it.
Risk Factors and Symptoms
The risk factors for prediabetes are largely the same as those for type 2 diabetes:
- Obesity or overweight
- Sedentary lifestyle
- Previous diagnosis of gestational diabetes (diabetes during pregnancy)
- Age over 45
- Family history of type 2 diabetes
- African-American, Hispanic/Latino, American Indian, Asian American, or Pacific Islander racial or ethnic heritage
Prediabetes generally has no signs or symptoms.
One of the few possible signs is acanthosis nigricans, which is a darkening of the skin in places such as the neck, armpits, elbows, knees, and knuckles.
If you notice such skin changes, it’s a good idea to get them checked out by a doctor.
Prediabetes may be discovered by chance if you undergo a routine blood test (at any age) or routine screening for type 2 diabetes (at age 45).
Or it may be discovered if you have risk factors for prediabetes and type 2 diabetes and your doctor orders a screening test.
The tests used to screen for prediabetes are the same as those used to screen for type 2 diabetes: the fasting plasma glucose test and the A1C test (also called the HbA1c test or the hemoglobin A1c test).
A fasting plasma glucose test result between 100 and 125 mg/dl and an HbA1c test result between 5.7 percent and 6.4 percent indicate prediabetes.
The oral glucose tolerance test (OGTT), which involves fasting overnight, then drinking a glucose solution and having blood sugar measured one hour and two hours afterward, is sometimes used to diagnose prediabetes.
However, that test is generally used only to screen for gestational diabetes because it’s more time-consuming and expensive than other tests.
The goal of treating prediabetes is to prevent or delay the onset of type 2 diabetes.
That goal is reachable, according to the landmark Diabetes Prevention Program (DPP) study, which examined the effects of weight loss through dietary changes and increased physical activity on people who have prediabetes.
The DPP study enrolled 3,234 overweight adults from 27 clinical centers around the United States; 45 percent of participants were members of racial or ethnic minority groups.
Participants who received intensive counseling and motivational support for improving their diets and being physically active reduced their risk of developing diabetes by 58 percent.
The methodology of the DPP has been adopted by the YMCA’s Diabetes Prevention Program, which is currently being implemented at participating Ys across the United States, as well as other sites.
That means many of the 79 million Americans with prediabetes now have access to an affordable — and proven — way of managing their prediabetes and preventing or delaying type 2 diabetes.
- Diabetes Prevention Program (DPP); National Diabetes Information Clearinghouse (NDIC).
- Prediabetes; Centers for Disease Control and Prevention (CDC).
- Prediabetes: Am I at risk?; Centers for Disease Control and Prevention (CDC).
- Prediabetes Symptoms; Mayo Clinic.
- YMCA’s Diabetes Prevention Program; YMCA.
Last Updated: 4/11/2016