Pre-Diabetes and Insulin Resistance
Pre-diabetes, also known as "impaired glucose tolerance," is a health condition with no symptoms. It is almost always present before a person develops the more serious type 2 diabetes. According to the American Diabetes Association, 54 million people in the U.S. over age 20 have pre-diabetes with blood glucose levels that are higher than normal, but are not high enough to be classified as diabetes.
More and more, doctors are recognizing the importance of diagnosing pre-diabetes as treatment of the condition may prevent more serious health problems. For example, early diagnosis and treatment of pre-diabetes may prevent type 2 diabetes as well as associated complications such as heart and blood vessel disease and eye and kidney disease. Doctors now know that the health complications associated with type 2 diabetes often occur before the medical diagnosis of diabetes is made.
Who's At Risk for Developing Type 2 Diabetes?
Those at risk for type 2 diabetes include:
People with a family history of type 2 diabetes.
Women who had gestational diabetes or have had a baby weighing more than 9 pounds.
Women who have polycystic ovary syndrome (PCOS).
African Americans, Native Americans, Latinos, and Pacific Islanders, minority groups that are disproportionately affected by diabetes.
People who are overweight or obese, especially around the abdomen (belly fat).
People with high cholesterol, high triglycerides, low good 'HDL' cholesterol and a high bad 'LDL' cholesterol.
People who are inactive.
Older people. As people age they are less able to process glucose appropriately and therefore have a greater risk of developing type 2 diabetes.
What Are the Symptoms of Pre-Diabetes?
Although most people with pre-diabetes have no symptoms at all, symptoms of diabetes may include unusual thirst, a frequent desire to urinate, blurred vision, or extreme fatigue.
A medical lab test may show some signs that suggest pre-diabetes may be present.
Who Should Be Tested for Pre-Diabetes?
You should be tested if:
You're over 45 years of age.
You have any risk factors for diabetes.
You're overweight with a BMI (body mass index) over 25.
You belong to a high risk ethnic group.
You were know to previously have an abnormal glucose tolerance test (see below) or have an impaired fasting glucose level (see below).
You have a history of gestational diabetes or delivering a baby that weighed more than 9 pounds.
You have clusters of problems seen in the metabolic syndrome. These problems include high cholesterol and triglycerides, high LDL cholesterol and low HDL cholesterol, central obesity, hypertension, and insulin resistance.
You have polycystic ovarian syndrome
How Is Pre-Diabetes Diagnosed?
To determine if you have pre-diabetes, your doctor can perform two different blood tests Ò the fasting plasma glucose (FPG) test and the oral glucose tolerance test (OGTT).
During the FPG blood test your blood glucose level is measured after an 8 hour fast. This laboratory health screening can determine if your body metabolizes glucose correctly. If your blood glucose level is abnormal after the fasting plasma glucose (FPG) test, you could have what's called "impaired fasting glucose," which suggests pre-diabetes.
Understanding the FPG Test Results
Normal Less than 100 mg/dL (milligrams per deciliter)
Pre-Diabetes 100 mg/dL - 125 mg/dL
Diabetes Greater than 126 mg/dL on two or more tests
The other laboratory health screening test your doctor can perform is the oral glucose tolerance test. During this test, your blood sugar is measured after a fast and then again 2 hours after drinking a beverage containing a large amount of glucose. Two hours after the glucose beverage, if your glucose is higher than normal, you have what's called "impaired glucose tolerance," which suggests pre-diabetes.
Understanding the OGTT Test Results
Normal Less than 140 mg/dL
Pre-Diabetes 140 mg/dL to 199 mg/dL
Diabetes Greater than 200 mg/dL
Why Is It Important to Recognize and Treat Pre-Diabetes?
By identifying the signs of pre-diabetes before diabetes occurs, you can prevent type 2 diabetes all together and lower your risk of complications associated with this condition, such as cardiovascular disease.
A large 3 year medical study in patients at risk of developing type 2 diabetes found that lifestyle changes with exercise and mild weight loss, and treatment with medications that work to sensitize a person to the actions of insulin, can decrease the chance that a person with pre-diabetes will get type 2 diabetes by up to 60%. Changing a person's lifestyle habits with increased physical activities and mild weight loss was more effective than medications at reducing the risk of developing type 2 diabetes. For some people with pre-diabetes, intervening early can actually return elevated blood glucose levels to the normal, healthy range.
Pre-Diabetes: What's the Treatment?
To successfully treat pre-diabetes:
Eat a heart healthy diet and lose weight. A 5% to 10% weight loss can make a huge difference.
Exercise. Try to exercise 30 minutes a day, 5 days a week. The activity can be split into several short periods: 3 sessions of 10 minutes. Select an activity that you enjoy such as walking. In the study mentioned above, the total amount of exercise per week was 150 minutes.
Treat high blood pressure and high cholesterol.
Reviewed by Certified Diabetes Educators in the Department of Patient Education and Health Information and by physicians in the Department of Endocrinology at The Cleveland Clinic.