and Exercise Sharply Cut Type 2 Diabetes Risk
By Ori Twersky
WASHINGTON (Reuters Health) - Americans at risk of developing
type 2 diabetes can sharply reduce the odds through a regular
regimen of diet and exercise, according to the nation's first
major clinical trial to compare the effects of diet and exercise
versus medication in the prevention of type 2 diabetes.
The trial, sponsored by the National Institutes of Health (NIH),
found that at-risk people who exercised at least 30 minutes a
day reduced their risk by 58%, even without medication. In
contrast, those who used the diabetes drug Glucophage (metformin)
without diet and exercise reduced the risk by only 31%. Type 2
diabetes is strongly associated with obesity.
"In view of the rapidly rising rates of obesity and
diabetes in America, this good news couldn't have come at a
better time," said Department of Health and Human Services
(HHS) Secretary Tommy Thompson, while releasing the results.
"So many of our health problems can be avoided through
diet, exercise and making sure we take care of ourselves."
Other experts agreed.
"I think common sense would have dictated this,"
Dr. William Crowley, a professor of medicine at Harvard
University in Boston, Massachusetts, and president of the
Endocrine Society, told Reuters Health. "But on the other
hand, this hypothesis has not been studied in the American
population. So, this really is a landmark."
The findings come from the Diabetes Prevention Program (DPP),
a large-scale clinical trial conducted at 27 centers nationwide
and involving more than 3,000 participants. Participants ranged
in age from 25 to 85, and were required to sustain a 5% weight
loss over the study's 3-year duration.
As a result, Crowley said the trial is likely to increase
physicians' resolve to talk to their patients about diet and
exercise. At present, Crowley said physicians are often
reluctant to aggressively recommend diet and exercise because
patients generally do not follow this advice. And until now,
there was no concrete evidence to establish that diet and
exercise alone could result in such a dramatic decrease in type
2 diabetes risk.
But the researchers cautioned that the jury has yet to submit
a final verdict.
"We simply don't know how long, beyond the 3-year period
studied, diabetes can be delayed," explained Dr. David
Nathan, the lead investigator.
Nathan added that further follow-up would be needed to
determine if the diet and exercise regimen also reduced the risk
of common concurrent conditions, such as heart disease--a major
cause of death in people with type 2 diabetes.
But overall, Nathan noted that the lifestyle changes worked
as well in men and women of all ages, while the drug therapy
appeared relatively ineffective in older people and those who
were relatively less overweight.
"Every year a person can live free of diabetes means an
added year of life free of pain, disability and medical costs
incurred by this disease," added Dr. Allen Spiegel,
director of the NIH division responsible for sponsoring the
trial. "The DPP findings represent a major step toward the
goal of containing and ultimately reversing the epidemic of type
2 diabetes in this country."
An estimated 16 million Americans have type 2 diabetes,
according to the Centers for Disease Control and Prevention (CDC).
Type 2 diabetes is also a major cause of kidney failure, limb
amputations and blindness in adults, according to CDC figures.
Glucophage was approved in 1996 as a treatment for
adult-onset diabetes that could not be managed using insulin
alone. Glucophage subsequently was also approved for the
prevention of type 2 diabetes in at-risk Americans aged 10 and
Praising the current study, Crowley said the NIH should now
involve itself in further research into type 2 diabetes
"I think there is no question that the NIH has to
continue and expand human investigation," Crowley told
Reuters Health. "Human experimentation is key."
Representatives from Bristol-Myers Squibb, the manufacturer
of Glucophage, could not be reached for immediate comment.