U.S. Teen Diabetes Higher than Estimated

More teens in the U.S. have diabetes or prediabetes than previously thought.

Many also don't know they have this disease, a new study discovered. Nearly 1 percent of more than 2,6-- teens studied had diabetes, with almost one in three cases undiagnosed. Of the 2,600, almost 20 percent had prediabetes – in the range of 100 mg/dl to 125 mg/dl.

"These findings are important because diabetes in youth is associated with early onset of risk factors and complications," said lead researcher Andy Menke of Social & Scientific Systems in Silver Spring, Md. One prior study estimated the prevalence of diabetes in teens at about 0.34 percent, but the current study shows it's double that -- 0.8 percent.

The researchers couldn't distinguish between teens that had type 1 or type 2 diabetes. However, previous research among children and teens with diabetes found that 87 percent had type 1 diabetes, previously called juvenile diabetes.

While type 1 diabetes, an autoimmune disease, isn't preventable, type 2 is usually related to lifestyle factors. Type 2 is generally seen in adults, but experts say it's risen among younger people as obesity rates have soared.

Dr. Joel Zonszein, director of the Clinical Diabetes Center at Montefiore Medical Center in New York City says, "It is alarming to see such a high incidence of [childhood] diabetes when it should be close to zero.” “The very high prevalence of prediabetes, diabetes and especially undiagnosed diabetes in adolescents is worrisome," he added. “The majority of those with prediabetes will develop diabetes if nothing is done to change their lifestyle,” Zonszein concluded.

African Americans and Hispanics were more likely than whites to have prediabetes or not know they had diabetes, the study found. There are effective treatments, but those treatments are not useful to people who have not been diagnosed. Untreated, diabetes can lead to heart disease, circulatory problems, vision loss, and amputation of feet and legs.

Classic symptoms include increased urination, increased thirst, weight loss (due to dehydration), and perhaps increased hunger and blurry vision. Previous studies have found that both type 1 and type 2 diabetes are increasing among adolescents.

According to the U.S. National Institute of Diabetes and Digestive and Kidney Diseases, being overweight or obese is the main cause of type 2 diabetes. People at high risk can prevent or delay its onset by losing 5 percent to 7 percent of their weight, the agency says. Because type 2 is considered lifestyle-related, better education on reducing risk factors for type 2 and improved screening for adolescents at high risk is needed. The agency recommends at least 30 minutes of moderate-intensity physical activity five days a week, and reducing daily calorie consumption.

Of 62 teens with diabetes, 29 percent didn't know it. Prevalence of prediabetes was 18 percent, and more common in boys. Among the diabetic teens, nearly 5 percent of whites had not been diagnosed versus 50 percent of the African Americans and 40 percent of Hispanics.