Diabetes :: Diet, exercise slow rising blood sugar levels

Pre-diabetes – the term, recently coined by health officials, indicates a partly elevated blood sugar level that will likely develop into full diabetes within 10 years if nothing is done to stop it.

Scientists now have proof that something can: a healthy diet and exercise.

Doctors have known for years that type 2, or adult-onset, diabetes usually comes on gradually, often as people gain weight.

Their insulin production dips or their bodies don’t use insulin effectively anymore; their blood sugar level rises, but not high enough to have diabetes right away.

Until recently, doctors didn’t know for sure if anything could be done to ward off diabetes in people whose blood sugar levels had started to creep up.

That changed three years ago. In a major study, researchers found that diet, exercise and certain medications can slow or even reverse the progression of pre-diabetes to diabetes. That can prevent diabetes complications such as blindness, kidney disease and amputation.

The landmark study has led health authorities on a twofold quest: Doctors want to identify the 41 million Americans thought to have pre-diabetes (another 18 million have diabetes; the vast majority, type 2) and encourage them to take action to improve their health.

“If you know you’re at risk and you can do something about it, it’s a powerful motivator,” said Dr. Michael Engelgau, with the national Centers for Disease Control and Prevention’s Division of Diabetes Translation.

The challenge is to pick out the people with pre-diabetes without wasting time and money testing a lot of people who don’t.

One approach is being studied at Emory University. Researchers are looking at expanding to the general population the two-step screening process routinely performed on pregnant women, who sometimes develop diabetes temporarily.

The Diabetes Prevention Program study, funded by the federal government and published in the New England Journal of Medicine in 2002, tracked 3,200 people with pre-diabetes. Those who exercised half an hour, five days a week, and lost 7 percent of their weight through a low-fat diet were 58 percent less likely to progress to diabetes after three years.

Other people who took the drug metformin were 31 percent less likely to get diabetes. Another trial found that another drug, acarbose, reduced the risk of diabetes by 25 percent.

“That was the turning point,” said Dr. Charles Clark of Indiana University, former chair of the National Diabetes Education Program. “It got everybody’s attention.”

The study led the American Diabetes Association to issue new guidelines: anyone 45 and older who is overweight should be checked for pre-diabetes, along with younger people who also have other risk factors, such as high blood pressure, low levels of HDL (or “good”) cholesterol or being African-American or Latino.

Some doctors are already testing more people for pre-diabetes.

But the two tests normally used aren’t patient-friendly.

The Emory study is looking at a simpler alternative, now done on pregnant women. It’s called a glucose challenge test. People have to drink a sugar solution, but they don’t have to fast. Blood is taken only once, and it’s possible a finger stick may do.

People who test positive would then take the more intensive oral glucose tolerance test, considered the gold standard for diagnosing pre-diabetes or diabetes. The study, which started in January and is funded by the National Institutes of Health, aims to test 2,100 people over three years. It is limited for now to employees of Emory, Grady Memorial Hospital and Morehouse School of Medicine in Atlanta and their family and friends.

If the Emory researchers find that the glucose challenge test works well in the general population — and is cost-effective — it could someday become part of routine medical checkups.