Diet, Exercise Slow Rising Blood Sugar Levels
Richard Mehlan knew he was at risk for diabetes. He is overweight, he has high blood fat levels, and his mother had the disease.
But until last month, the 57-year-old from Marietta didn't know he had "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.
Mehlan was one of the first people
in the Emory study found to have pre-diabetes.
He wasn't surprised: At 6 feet 2, he
weighs 295 pounds; his triglycerides, or levels of fat in the blood, are
high; his mother, who died two years ago, had diabetes.
Mehlan had already been trying to
eat better and exercise more, but the news of having pre-diabetes has
given those efforts a boost. Now he's cooking broccoli, cauliflower and
chicken --- baked, not fried --- and trying to walk half an hour a day.
As spring approaches, he is also
planning to get more physical activity out of mowing the lawn.
There is strong evidence that making
lifestyle changes, as Mehlan is doing, helps.
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 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. Who should be tested? People 45 and
older who are overweight; younger adults who are overweight and have other
risk factors: high blood pressure, high triglycerides, low HDL ("good"
cholesterol), a family history of diabetes, gestational diabetes or birth
to a child more than 9 pounds, being African-American or Latino. What tests are performed: fasting plasma glucose test
or oral glucose tolerance test. Both require fasting and blood drawn from
the arm; the tolerance test also requires a sugar drink and a second blood
draw and takes two hours. > What is new: Researchers at Emory University
are looking at screening more of the general public for pre-diabetes with
a test routinely given to pregnant women. It doesn't require fasting, and
it may involve only a finger stick. The study is limited for now to
employees and associates at Emory, Grady Memorial Hospital and Morehouse
School of Medicine. Sources: American Diabetes Association, Emory
University