Cambridge News Flash........

Diet 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 older.

Praising the current study, Crowley said the NIH should now involve itself in further research into type 2 diabetes prevention.

"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.