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.
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. 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.
But research has also shown that if you take action to control your blood glucose when you have pre-diabetes, you can delay or prevent type 2 diabetes from ever developing. The American Diabetes Association has just published a Position Statement on "The Prevention or Delay of Type 2 Diabetes" to help guide health care professionals in treating their patients with pre-diabetes.
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. The American Diabetes Association has a wealth of resources for people with diabetes. People with pre-diabetes can expect to benefit from much of the same advice for good nutrition and physical activity. .
The scientific and medical basis for identifying pre-diabetes as a serious health threat is laid out in a new Position Statement entitled "The Prevention or Delay of Type 2 Diabetes". The statement has been issued jointly by the American Diabetes Association and the National Institute of Diabetes and Digestive and Kidney Diseases.
HOW DO YOU TELL IF YOU HAVE PRE-DIABETES?
There are two different tests your doctor can use to determine whether you have pre-diabetes: the fasting plasma glucose test (FPG) or the oral glucose tolerance test (OGTT). The blood glucose levels measured after these tests determine whether you have a normal metabolism, or whether you have pre-diabetes or diabetes. If your blood glucose level is abnormal following the FPG, you have impaired fasting glucose (IFG); if your blood glucose level is abnormal following the OGTT, you have impaired glucose tolerance (IGT).
WHATYOU CAN DO
Pre-diabetes is a serious medical condition that can be treated. The good news is that the recently completed Diabetes Prevention Program study conclusively showed that people with pre-diabetes can prevent the development of type 2 diabetes by making changes in their diet and increasing their level of physical activity. They may even be able to return their blood glucose levels to the normal range.
While the DPP also showed that some medications may delay the development of diabetes, diet and exercise worked better. Just 30 minutes a day of moderate physical activity, coupled with a 5-10% reduction in body weight, produced a 58% reduction in diabetes.
The American Diabetes Association is developing materials that will help people understand their risks for pre-diabetes and what they can do to halt the progression to diabetes and even to, "turn back the clock." In the meantime, ADA has a wealth of resources for people with diabetes or at risk for diabetes that can be of use to people interested in pre-diabetes.
FREQUENTLY ASKED QUESTIONS
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 3 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 tested 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 110 mg/dl. A person with pre-diabetes has a fasting blood glucose level between 110 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: Which test is better?
A: According to the expert panel, either test is appropriate to identify pre-diabetes.
Q: Why do I need to know if I have pre-diabetes?
A: If you have pre-diabetes, you can and should do something about it. Studies have shown that people with pre-diabetes can prevent or delay the development of type 2 diabetes by up to 58 percent through changes to their lifestyle that include modest weight loss and regular exercise. The expert panel recommends that people with pre-diabetes reduce their weight by 5-10 percent and participate in some type of modest physical activity for 30 minutes daily. For some people with pre-diabetes, intervening early can actually turn back the clock and return elevated blood glucose levels to the normal range.
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 tested 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.
Q: How often should I be tested?
A: If your blood glucose levels are in the normal range, it is reasonable to be retested every 3 years. If you have pre-diabetes, you should be tested for type 2 diabetes every 1-2 years after your diagnosis.
Q: Could I have pre-diabetes and not know it?
A: Absolutely. People with pre-diabetes don't often have symptoms. In fact, millions of people have diabetes and don't know it because symptoms develop so gradually, people often don't recognize them. Some people have no symptoms at all. Symptoms of diabetes include unusual thirst, a frequent desire to urinate, blurred vision, or a feeling of being tired most of the time for no apparent reason.
Q: Should children be screened for pre-diabetes?
A: We are not recommending screening children for pre-diabetes because we don't have enough evidence that type 2 diabetes can be prevented or delayed in children at high risk for the disease. However, a study published in the March 14, 2002, issue of the New England Journal of Medicine found 25 percent of very obese children and 21 percent of very obese adolescents had pre-diabetes. If future studies show that early intervention also works for children, a recommendation could be forthcoming