Obese but otherwise healthy adolescents may benefit from a drug commonly used to treat type-2 diabetes, say Lucile Packard Children's Hospital researchers. The researchers have recently initiated a two-year randomized trial to test whether the drug, metformin, can help overweight teens shed excess pounds -- reducing their future risk of heart disease, high blood pressure and diabetes.

"There is some evidence that metformin causes weight loss in children with type-2 diabetes," said pediatric endocrinologist Darrell Wilson, MD. "Now we're trying it in obese children who don't have the disease."

Wilson, professor of pediatrics at the Stanford University School of Medicine, is the study's principal investigator.

As a diabetes treatment, metformin works by increasing the body's sensitivity to insulin, which signals cells to remove sugar from the blood. It also decreases the manufacture of sugar by the liver and its absorption by the intestines.

The study, which is sponsored by the Glaser Pediatric Research Network, will be conducted at five sites across the country, including Packard Children's Hospital and UC-San Francisco Medical Center.

To be eligible, adolescents between ages 13 and 17 must have a body mass index, or BMI, that exceeds the 95th percentile for their age and gender. Measurements such as BMI take into account an individual's height and weight, and average values vary by age and gender.

Volunteers will be given a glucose tolerance test to ensure they don't already have diabetes before being randomized into one of two groups. For the first year, one group will receive metformin and the other will take a placebo. Both groups also will attend regular diet and exercise education classes. During the second year, researchers will follow the weight loss or gain in each group without medication.

The researchers are planning to enroll 75 patients, 15 at each of the five sites across the country. Participants will receive some financial support to defray travel expenses incurred during 11 visits to the study site over the course of the investigation.

In addition to undergoing physical exams and answering questions about their health and diet, volunteers will be asked to wear an activity monitor for five five-day stretches during the two years.

For more information about the study, call 650-724-7123 or 650-724-7119, or visit the Web site for the Division of Pediatric Endocrinology and Diabetes at www.med.stanford.edu/dped/. Links to the BMI-for-age growth charts for children ages 2 to 20 can be found under "Clinical Growth Charts" at http://www.cdc.gov/growthcharts/.

Stanford University Medical Center integrates research, medical education and patient care at its three institutions -- Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children's Hospital at Stanford. For more information, please visit the Web site of the medical center's Office of Communication & Public Affairs at http://mednews.stanford.edu.

Lucile Salter Packard Children's Hospital at Stanford is a 240-bed hospital devoted entirely to the care of children and expectant mothers. Providing pediatric medical and surgical services associated with Stanford University Medical Center, Packard offers patients locally, regionally and nationally the full range of health-care programs and services -- from preventive and routine care to the diagnosis and treatment of serious illness and injury. To learn more about Lucile Packard Children's Hospital, please visit our Web site at www.lpch.org.