Pre-diabetes: what you need to know

Before people develop type 2 diabetes, they almost always have "pre-diabetes"--blood glucose levels that are higher than normal, but not yet high enough to be diagnosed as diabetes. There are 41 million people in the United States, ages 40 to 74, who have pre-diabetes. Recent research has shown that some long-term damage to the body, especially the heart and circulatory system, may already be occurring during pre-diabetes.

Research has also shown that if you take action to manage your blood glucose when you have pre-diabetes, you can delay or prevent type 2 diabetes from developing. There is a lot you can do yourself to know your risks for pre-diabetes and to take action to prevent diabetes if you have, or are at risk for, pre-diabetes, including healthy eating and exercise. The following are frequently asked questions pertaining to pre-diabetes.

Q: What is pre-diabetes and how is it different from diabetes?

A: Pre-diabetes is the state that occurs when a person's blood glucose levels are higher than normal but not high enough for a diagnosis of diabetes. About 11 percent of people with pre-diabetes in the Diabetes Prevention Program standard or control group developed type 2 diabetes each year during the average three years of follow-up. Other studies show that most people with pre-diabetes develop type 2 diabetes in 10 years.

Q: Is pre-diabetes the same as Impaired Glucose Tolerance or Impaired Fasting Glucose?

A: Yes. Doctors sometimes refer to this state of elevated blood glucose levels as Impaired Glucose Tolerance or Impaired Fasting Glucose (IGT/IFG), depending on which test was used to detect it.

Q: Why do we need to give it a new name? Has the condition changed?

A: The condition has not changed, but what we know about it has. We are giving IGT/IFG a new name for several reasons. Pre-diabetes is a clearer way of explaining what it means to have higher than normal blood glucose levels. It means you are likely to develop diabetes and may already be experiencing the adverse health effects of this serious condition. People with pre-diabetes are at higher risk of cardiovascular disease. People with pre-diabetes have a 1.5-fold risk of cardiovascular disease compared to people with normal blood glucose. People with diabetes have a 2- to 4-fold increased risk of cardiovascular disease. We now know that people with pre-diabetes can delay or prevent the onset of type 2 diabetes through lifestyle changes.

Q: How do I know if I have pre-diabetes?

A: Doctors can use either the fasting plasma glucose test (FPG) or the oral glucose tolerance test (OGTT) to detect pre-diabetes. Both require a person to fast overnight. In the FPG test, a person's blood glucose is measured first thing in the morning before eating. In the OGTT, a person's blood glucose is checked after fasting and again 2 hours after drinking a glucose-rich drink.

Q: How does the FPG test define diabetes and pre-diabetes?

A: Normal fasting blood glucose is below 100 mg/dl. A person with pre-diabetes has a fasting blood glucose level between 100 and 125 mg/dl. If the blood glucose level rises to 126 mg/dl or above, a person has diabetes.

Q: How does the OGTT define diabetes and pre-diabetes?

A: In the OGTT, a person's blood glucose is measured after a fast and 2 hours after drinking a glucose-rich beverage. Normal blood glucose is below 140 mg/dl 2 hours after the drink. In pre-diabetes, the 2-hour blood glucose is 140 to 199 mg/dl. If the 2-hour blood glucose rises to 200 mg/dl or above, a person has diabetes.

Q: Will my insurance cover testing and treatment?

A: Because all insurance plans are different, this is a difficult question to answer. However, Medicare and most insurance plans cover diabetes testing for people suspected of having diabetes. People at risk for diabetes are also at risk for pre-diabetes. Since the test is the same and the risk factors are the same for both conditions, a pre-diabetes test may be covered. It is best to consult your physician and health insurance representative with specific coverage questions.

Q: What is the treatment for pre-diabetes?

A: Treatment consists of losing a modest amount of weight (5-10 percent of total body weight) through diet and moderate exercise, such as walking 30 minutes a day, 5 days a week. Don't worry if you can't get to your ideal body weight. A loss of just 10 to 15 pounds can make a huge difference. If you have pre-diabetes, you are at a 50 percent increased risk for heart disease or stroke, so your doctor may wish to treat or counsel you about cardiovascular risk factors, such as tobacco use, high blood pressure and high cholesterol.

Q: Who should get tested for pre-diabetes?

A: If you are overweight and age 45 or older, you should be checked for pre-diabetes during your next routine medical office visit. If your weight is normal and you're over age 45, you should ask your doctor during a routine office visit if testing is appropriate. For adults younger than 45 and overweight, your doctor may recommend testing if you have any other risk factors for diabetes or pre-diabetes. These include high blood pressure, low HDL cholesterol and high triglycerides, a family history of diabetes, a history of gestational diabetes or giving birth to a baby weighing more than 9 pounds, or belonging to an ethnic or minority group at high risk for diabetes.