The five-year TODAY (Treatment Options for type 2 Diabetes in Adolescents and Youth), which will compare three treatments, is sponsored by the U.S. National Institute of Diabetes and Digestive and Kidney Diseases, which is part of the National Institutes of Health (NIH).

"Type 2 diabetes has increasingly become a problem in our young people. This trial will give us the information we need to most effectively help these patients," NIH director Elias A. Zerhouni says in a prepared statement.

Researchers plan to enroll 750 children aged 10 to 17 years old who have been diagnosed with type 2 diabetes in the past two years. The children and teens will be randomly assigned to receive one of three treatments: metformin (brand name Glucophage) alone; metformin and rosiglitazone (brand name Avandia) in a fixed-dose combination; and metformin plus intensive lifestyle change aimed at increasing physical activity and weight loss.

About 18.2 million people -- 6.3 percent of the U.S. population -- have diabetes, which is the main cause of kidney failure, limb amputations and new onset blindness in adults. It's also a major cause of stroke and heart disease.

Type 2 diabetes, which is most common in adults over age 40, accounts for the vast majority of all diabetes cases. The prevalence of type 2 diabetes has greatly increased over the past three decades, due mostly to rising rates of obesity.