People with pre-diabetes should lose weight and exercise at least 30 minutes a day, a group of experts said February 27. This advice is part of the first formal guidelines for treatment of pre-diabetes. With this condition, blood sugar is higher than normal. However, it is lower than in diabetes. The American Diabetes Association convened the panel of experts that issued the guidelines. The purpose is to prevent diabetes in people who have pre-diabetes. In some cases, the drug metformin may help. The guidelines list criteria to help doctors decide when to prescribe it.

By Mary Pickett, M.D.
Harvard Medical School

What Is the Doctor's Reaction?

Are you one of the 21 million Americans who qualify for a diagnosis of "pre-diabetes"? You have pre-diabetes if your blood sugar on a fasting blood test is high, but not high enough to indicate diabetes. And if you are a person with pre-diabetes, do you need treatment?

Blood sugar testing has been around for a long time. Pre-diabetes, however, is a relatively new term. It has been used as a diagnosis for less than a decade.

A fasting blood sugar (glucose) level that is at least 100 but no more than 125 is in the pre-diabetes range.

Until now, doctors have given individual advice to patients with pre-diabetes. They have not had the benefit of expert guidelines. This week, a panel of experts has issued the first formal guidelines for treatment of pre-diabetes. The panel was organized by the American Diabetes Association (ADA).

If you have pre-diabetes, you have about a 10% chance of developing diabetes within one year. Your chance of developing diabetes during your lifetime is roughly 70%.

People with pre-diabetes have a higher risk of heart disease than average, even before diabetes develops. With the onset of diabetes, your risk of heart disease and stroke increases sharply. This is an important reason to do what you can to delay or prevent diabetes.

With pre-diabetes, you can lower your chances of developing diabetes by using diet and exercise. Some people also may benefit from using a medicine.

The guidelines are based on sound evidence that has been collected in several large studies during the last 5 to 10 years. The recommendations will mean more blood tests and renewed prevention efforts for most people with pre-diabetes.

What Changes Can I Make Now?

The ADA guidelines say that people with pre-diabetes should aim to lose 5% to 10% of their body weight through diet and exercise. They should exercise at least 30 minutes per day.

These steps can reduce by nearly 60% the chances that pre-diabetes will turn into full-blown diabetes within three years. There is nothing controversial about this recommendation. It is based upon very clear evidence.

For some people, the guidelines suggest adding a medicine -- metformin (Glucophage) -- to your diabetes prevention strategy. Metformin doesn't provide as strong a benefit as weight loss and exercise do, but it can help maximize your efforts to avoid diabetes.

The panel of experts says that people who have the highest risk of developing diabetes should be the ones to consider metformin treatment. Several test results and personal characteristics are used to determine whether you have an extra high risk.

The guidelines lay out a three-step process to show whether the ADA would recommend metformin in your case. These steps are for people who have been diagnosed with pre-diabetes, based on a high fasting glucose measurement.

Step 1: You should have additional blood tests to know your cholesterol levels and your average blood sugar (A1C).

Step 2: With those results, you and your doctor should review the following list to see if any one of these features applies to you:

• Age below 60
• Obesity, with a body mass index (BMI) of 35 or higher
• Diabetes in a parent or sibling
• High triglycerides
• Low HDL cholesterol
• High blood pressure
• A1C test result greater than 6%

If you have any of these listed criteria, proceed to Step 3.

Step 3: With any one of the risk factors on the list above, the ADA recommends that you have an oral glucose tolerance test. This blood test can measure your glucose level two hours after you drink a sugary beverage. The drink is provided by your doctor or laboratory. It includes a standard amount of glucose. If your blood sugar is higher than 140 after this drink, you are a good candidate for metformin.

Metformin is not appropriate for everyone. The ADA considers drug treatment to be optional, even if you match these criteria. However, metformin combined with diet and exercise will give you the best chance of avoiding or delaying diabetes. This will help to keep your risk of heart attack, stroke and other complications of diabetes as low as possible, for as long as you can.

What Can I Expect Looking to the Future?

We are still learning about what leads to pre-diabetes and diabetes. We know that the cause of both conditions is insulin resistance. This is a sluggishness of muscle cells and liver tissue to react to the hormone insulin. Insulin allows cells to use glucose to produce energy.

What we don't know is the cause of insulin resistance. Excess weight contributes to it. Evidence suggests that diet choices and environmental toxins also may contribute.

We also don't know for sure how much we might gain from pre-diabetes treatment. It is clear that diet and exercise, with or without metformin, can reduce the chance of developing diabetes. We do not have proof, however, that these changes will reduce the risk of h  [report anonymous abuse]

We are still learning about what leads to pre-diabetes and diabetes. We know that the cause of both conditions is insulin resistance. This is a sluggishness of muscle cells and liver tissue to react to the hormone insulin. Insulin allows cells to use glucose to produce energy.

What we don't know is the cause of insulin resistance. Excess weight contributes to it. Evidence suggests that diet choices and environmental toxins also may contribute.

We also don't know for sure how much we might gain from pre-diabetes treatment. It is clear that diet and exercise, with or without metformin, can reduce the chance of developing diabetes. We do not have proof, however, that these changes will reduce the risk of heart attacks, stroke and premature death for people with pre-diabetes. The risk probably will be lower. The experts are betting on it. They probably will be proven right in time.