TUESDAY, June 28 (HealthDay News) -- Preventing type 2 diabetes not only improves an individual's quality of life, it also saves quite a bit of money.

By treating people who were at high risk for developing type 2 diabetes, researchers reduced medical costs by $2,600 for each person enrolled in a lifestyle changes group, and by $1,500 for each of those taking the diabetes drug metformin over the course of 10 years.

But when the savings in medical care were balanced against the costs of the interventions, metformin saved $30 over 10 years, while the lifestyle intervention cost $1,700 over the same time span.

"Compared to doing nothing to prevent type 2 diabetes, metformin is cost-saving as an intervention. Lifestyle intervention, though not cost-saving, is cost-effective," Dr. William Herman, a study author and professor of medicine and epidemiology at the University of Michigan, told an American Diabetes Association (ADA) press conference.

Herman noted that during the 10-year study follow-up, lifestyle intervention reduced the rate of diabetes by 34 percent, while metformin reduced the rate of type 2 diabetes by 18 percent.

Herman was scheduled to present the study's findings on Tuesday at the ADA's Scientific Sessions in San Diego.

The data for this study came from the Diabetes Prevention Program, which included more than 3,000 people who were at high risk of developing type 2 diabetes. They were all overweight and were considered to have pre-diabetes. They also had additional risk factors for developing type 2 diabetes.

The participants were randomly placed into one of three groups: lifestyle intervention, metformin treatment or placebo pills.

The lifestyle intervention group received one-on-one training in diet, exercise and behavioral modification. The goal was to lose 7 percent of body weight and to exercise at least 150 minutes a week. The metformin group was given 850 milligrams of the drug twice daily, and the placebo group received inactive placebo pills to take twice a day.

The initial phase of the study lasted three years, and found that lifestyle interventions reduced the rate of diabetes by 58 percent, while metformin dropped the incidence of diabetes by 31 percent, according to Herman.

The researchers continued to follow the study participants for the next seven years so they could assess economic costs. Herman said the current study doesn't take into account whether or not people continued on their prescribed regimens, just at the groups they had initially been in.

When the researchers reviewed the data to assess what the cost was per quality of life-adjusted year, they found that metformin was still cost saving, while lifestyle interventions required an investment.

Herman said the costs put metformin in the same category of interventions that you "broadly apply without question," such as prenatal care, childhood immunizations and flu shots for people over 65 years old. Lifestyle interventions, on the other hand, were in the same cost category per quality of life-adjusted year as high blood pressure medications for those with high diastolic (the bottom number) blood pressure, cholesterol-lowering medications for people who've already had a heart attack, and the use of heart medications known as beta blockers.

"Both of these are effective interventions, and both should be made available to at-risk individuals," said Herman.

"With pre-diabetes, the sooner we intervene, the better," said Dr. Joel Zonszein, director of the clinical diabetes program at Montefiore Medical Center in New York City. "If we wait until someone has type 2, it may be too long. In general, it's cost effective. Treating complications is more costly."

Because one-on-one lifestyle intervention training can be quite costly, and may not be paid for by insurance companies, Zonszein's center developed group classes for people with type 2 diabetes that met for several hours every quarter. They compared this group to people receiving one-on-one training. The researchers found that both groups were able to reduce their long-term blood sugar control. Zonszein's findings were presented in a poster at the ADA meeting.

Herman said that his group expected that the costs of lifestyle intervention would come down, probably through group interventions instead of one-on-one training.

"Doing lifestyle interventions as a group intervention may be less expensive, and may be more effective because of the social bonding aspect," he said.

More information

Visit the American Diabetes Association to learn your risk of type 2 diabetes.