The global epidemic of type 2 diabetes in adults is now spreading to children.

Less than two decades ago, type 2 diabetes was virtually unheard of among children and accounted for less than 3 percent of new diabetes cases among children and adolescents.

But a new study shows that type 2 diabetes now accounts for up to 45 percent of new diabetes cases among adolescents worldwide. The rate of type 2 diabetes among younger children is also rising dramatically.

Researchers say the rapid rise of type 2 diabetes in young people follows a similar rise among adults and is largely due to soaring obesity rates.

Obesity is a major risk factor for type 2 diabetes. Weight gain, poor nutrition, and lack of exercise hamper the ability of the hormone insulin to do its job and regulate blood sugar levels. The body initially compensates by producing more insulin to normalize blood sugars. Eventually the pancreas can't keep up and blood sugar levels rise, leading to the diagnosis of type 2 diabetes.

Children Next in Diabetes Epidemic

Type 2 diabetes was first recognized as an emerging problem in children in the U.S. in the 1990s. Similar rates are now being reported in Europe, Asia, and other parts of the world.

In the study, which appears in the May issue of the Journal of Pediatrics, researchers reviewed published reports on type 2 diabetes in children and adolescents between 1978 and 2004 worldwide.

Researchers found that there appears to be a close relationship between type 2 diabetes rates in adults in a particular region or ethnic group and the eventual appearance of the disease in children and adolescents in the same group. Type 2 diabetes in children was diagnosed earliest in those countries with the highest rates of type 2 diabetes among adults.

Based on information gathered from these international studies, researchers estimate that up to 45 percent of all new diabetes cases in adolescents are classified as type 2 diabetes.

Ethnic Groups at Risk

The study also shows that the growth of type 2 diabetes within ethnic groups is particularly dramatic.

For example, 80 percent of new diabetes cases among children in Japan and 70 percent of new cases among Native Americans are now type 2 diabetes compared with the 45 percent global average.

The report also shows that the Pima Indians in Arizona have the world's highest rates of type 2 diabetes in adults in addition to the highest rates of obesity, which is now leading to rising type 2 diabetes rates among the children in this group.

Other regions reporting higher percentages of type 2 diabetes among children and adolescents include New York City, Taiwan, New Zealand, and Canada.

Researchers say the study shows that obesity-related illnesses like type 2 diabetes are quickly becoming a global problem that requires major lifestyle changes among the affected peoples to reverse this trend.

By Jennifer Warner, reviewed by Brunilda Nazario, MD

SOURCES: Pinhas-Hamiel, O. Journal of Pediatrics, May 2005; vol 146: pp 693-700. News release, Journal of Pediatrics.