Exams and Tests
Your doctor will use a
medical history,
physical examination, and blood glucose testing to
determine whether you have
prediabetes and are at risk for developing
type 2 diabetes.
Blood glucose testing is usually done after fasting overnight for 8 hours. In some
cases, an
oral glucose tolerance test (OGTT) may be done. For an
OGTT, your blood sugar is measured after fasting and then again 2 hours after
drinking a special glucose solution. This test is not done as often as the
fasting glucose test, which is more convenient.
If the results
of your glucose tests are in one of the following ranges, you have prediabetes
and are at risk of developing type 2 diabetes:
- Fasting glucose of 100 to 125
milligrams per deciliter (mg/dL)
- Oral glucose tolerance (OGT) of 140 to 199 mg/dL (2 hours after
the beginning of the test)
Phrases such as "a touch of diabetes,” “borderline
diabetes,” or “your sugar is a little high” are unclear. If you hear these
phrases, ask whether your blood sugar level falls within the prediabetes or
diabetes range.
If you are diagnosed with prediabetes or type 2
diabetes, your doctor may also do a thorough examination of the
cardiovascular system
and check your
blood pressure and
cholesterol levels. Your doctor may also test your
blood sugar periodically to check for diabetes.
Early Detection
The American Diabetes Association
recommends screening for prediabetes, which may lead to type 2 diabetes, if
you2:
- Are 45 years of age or older—particularly if you are
overweight—and you have never had your blood glucose (sugar) tested or you have
not been tested in more than 3 years.
- Are younger than 45, overweight—body mass index, BMI, of 25 or greater—and have one or more other risk factors for
type 2 diabetes. These include:
- High blood pressure, over 140/90
millimeters of mercury (mm Hg).
- Abnormal cholesterol. People who have
high-density lipoprotein (HDL) cholesterol levels of
35 milligrams per deciliter (mg/dL) or less or
triglyceride levels of 250 mg/dL or more are at
increased risk for developing type 2 diabetes.4
- A family history of type 2 diabetes. People who have a
parent, brother, or sister with prediabetes or type 2 diabetes have a greater
risk of developing the disease than adults without a parental history of the
disease.
- History of
gestational diabetes or having a baby weighing more
than 9 lb (4 kg). Women who have had gestational diabetes or who have had a
large baby are at greater risk for getting type 2 diabetes later in
life.4
- Race and ethnicity. African Americans, Hispanics, Native
Americans, Asian Americans, and Pacific Islanders are at greater risk for
getting type 2 diabetes than whites.4
- Are overweight and get little or no exercise and want to help
reduce your risk for getting type 2 diabetes.
The United States Preventive Services Task Force (USPSTF) recommends diabetes testing for people who
have blood pressure greater than 135/80.10