Islets of Hope for persons with prediabetes
Article by Lahle Wolfe, 03/25/2006. For reprint information e-mail Editor@isletsofhope.com
Confused? See our Chart Comparison between Insulin Resistance, Insulin Resistance Syndrome (IRS), Prediabetes, Types 1 and 2 Diabetes, and Gestational Diabetes detailing the symptoms, diagnosis, treatment, and prognosis of these major metabolic disorders.
Impaired Glucose Tolerance (IGT) - It is estimated that approximately 20 million people in the U.S have IGT. Those who are at increased risk for developing IGT or type 2 diabetes include those who are overweight, have a family history of diabetes, had/have gestational diabetes, those with hypertension, elevated triglycerides, or another disorder associated with the risk of developing diabetes.
Those with IGT should be under the medical care of a qualified endocrinologist. Treatment may include lifestyle changes, medication, and monitoring blood glucose levels.
Prediabetes - Doctors sometimes call this condition impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), depending on the test used to diagnose it. In a cross-section of U.S. adults aged 40 to 74 tested during the period 1988 to 1994, 33.8 percent had IFG, 15.4 percent had IGT, and 40.1 percent had pre-diabetes (IGT or IFG or both). Applying these percentages to the 2000 U.S. population, about 35 million adults aged 40 to 74 would have IFG, 16 million would have IGT, and 41 million would have prediabetes.
(NIH Publication No. 04–4893, May 2004)
Did You Know?
... that prediabetes increases your risk of getting type 2 diabetes and of having heart disease or a stroke?
... that prediabetes can be reversed without insulin or medication by losing a modest amount of weight and increasing your physical activity?
... that an international expert committee of the American Diabetes Association recently redefined the criteria for prediabetes, lowering the blood sugar level cut-off point for pre-diabetes?
Approximately 20% more adults are now believed to have this condition and may develop diabetes within 10 years if they do not exercise or maintain a healthy weight.
Prediabetes: Impaired glucose tolerance and impaired fasting glucose
According to the NIH,, prediabetes is a term used to distinguish people who are at increased risk of developing diabetes. People with prediabetes have impaired fasting glucose (IFG) or impaired glucose tolerance (IGT). Some people may have both IFG and IGT.
IFG is a condition in which the fasting blood sugar level is elevated (100 to 125 milligrams per deciliter or mg/dL) after an overnight fast but is not high enough to be classified as diabetes.
IGT is a condition in which the blood sugar level is elevated (140 to 199 mg/dL) after a 2-hour oral glucose tolerance test, but is not high enough to be classified as diabetes.
In a cross-section of U.S. adults aged 40-74 years who were tested from 1988 to 1994, 33.8% had IFG, 15.4% had IGT, and 40.1% had prediabetes (IGT or IFG or both). Were these percentages applied to the 2000 U.S. population, about 35 million adults aged 40-74 would have IFG, 16 million would have IGT, and 41 million would have prediabetes.
Progression to diabetes among those with prediabetes is not inevitable. Studies suggest that weight loss and increased physical activity among people with prediabetes prevent or delay diabetes and may return blood glucose levels to normal.
People with prediabetes are already at increased risk for other adverse health outcomes such as heart disease and stroke.
Diagnosing prediabetes (or, pre-diabetes)
IOH Health Tip: Those with prediabetes, who do nothing about it, will most likely develop type 2 diabetes within 10 years of being diagnosed with prediabetes. But by making healthy changes in your lifestyle now you can reduce this risk significantly, and may even be able to completely reverse prediabetes by "retraining" your body how to properly use its own insulin.
There are two tests that can help your doctor diagnose whether or not you have prediabetes: the morning fasting glucose test and the 2-hour oral glucose tolerance test. These tests give only indirect evidence of insulin resistance so it may be important to also have fasting insulin levels checked if you suspect insulin resistance (insulin should also be checked at the 2-hour mark when blood glucose is checked during a 2-hour oral glucose tolerance test).
If tests show that you have impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), your doctor may suggest changes in diet and exercise to reduce your risk of developing type 2 diabetes.
Morning fasting glucose test
This test measures blood glucose (also called blood sugar) after you have been fasting over night for at least 8 hours. A blood sample is drawn in the doctor's office or lab, preferably in the morning before you eat. This test is performed to determine if you have impaired fasting glucose (IFG). This simply means that your doctor is checking to see if your blood glucose levels are normal, or above normal (impaired), in the morning before eating or drinking (water is fine, beverages with sugar or calories may not be consumed prior to the test). The following diagnostic criteria for prediabetes is based upon the recommendation of the American Diabetes Association (ADA):
Morning Fasting Blood Glucose
IFG does not happen overnight and you may have been insulin resistance for some time. Both insulin resistance and prediabetes are considered significant risk factors for developing type 2 diabetes. But it is important to remember that there is still time to change things. IFG is a prediabetic state, meaning that although you are more likely to develop type 2 diabetes, you do not have it yet.
Your doctor may either repeat the morning fasting glucose test, or want to do an Oral Glucose Tolerance Test (OGTT) before making a diagnosis and to see how your body responds to ingesting glucose (carbohydrates).
2-hour oral glucose tolerance test (OGTT)
The oral glucose tolerance test (OGTT) (which may also be called glucose tolerance test (GTT)), is a test that measures your blood glucose twice on the same day:
The following diagnostic criteria for prediabetes is based upon the recommendation of the American Diabetes Association (ADA):
Oral Glucose Tolerance Test Ranges
Additional glucose tests
For more complete information and charts on normal and abnormal blood glucose levels, including those used to diagnose prediabetes, diabetes, gestational diabetes, and target ranges for persons with diabetes, see:
Normal and Target Blood Glucose Ranges for
Books about insulin resistance syndrome (metabolic syndrome)
Page Updated 02/04/2009