April 21 (UPI) -- Researchers are trying to determine the cause of the significant increases in the number of newly diagnosed cases of type 1 and type 2 diabetes in U.S. youth.
The SEARCH for Diabetes in Youth Study, conducted by the Centers for Disease Control and Prevention, or CDC, and the National Institutes of Health, or NIH, found that from 2002 to 2012, the rate of newly diagnosed cases of type 1 diabetes in youth increased about 1.8 percent per year, and the rate of newly diagnosed cases of type 2 diabetes increased by 4.8 percent.
The study, published in the New England Journal of Medicine, included 11,244 children and teenagers from birth to age 19 with type 1 diabetes, and 2,846 children and teens age 10 to 19 with type 2 diabetes.
Type 1 diabetes is an autoimmune disease in which the beta cells of the pancreas are attacked by the immune system destroying their ability to make insulin. A genetic predisposition increases risk for the condition, specific causes of its development are not known.
In type 2 diabetes, the body develops insulin resistance due to long-term excess glucose in the diet, sending insulin-producing cells first into overdrive and then failure because they can't produce the proper level of insulin. Type 2 diabetes also has a genetic predisposition, but is often caused by obesity and lifestyle.
The study is the first to estimate trends in newly diagnosed cases of type 1 and type 2 diabetes in youth from five major racial/ethnic groups in the United States including non-Hispanic whites, non-Hispanic blacks, Hispanics, Asian Americans/Pacific Islanders and Native Americans.
Researchers found the rate of newly diagnosed cases of type 1 diabetes increased most sharply in Hispanic youth resulting in a 4.2 percent increase annually. In non-Hispanic blacks, the rate increased by 2.2 percent and in non-Hispanic whites the rate increased by 1.2 percent per year.
The study also showed the rate of new diagnosed cases of type 2 diabetes, which is rare in children, increased 8.9 percent in Native Americans, 8.5 percent in Asian Americans/Pacific Islanders, 6.3 percent in non-Hispanic blacks, 3.1 percent in Hispanics and 0.6 percent in whites.
"The increase we are seeing in type 2 diabetes in children is parallel to the increase in the incidence of obesity," Dr. Giuseppina Imperatore, an epidemologist in the CDC's Division of Diabetes Translation, told UPI.
The increase in cases of type 1 diabetes, however, is the subject of increasing scientific study. Some researchers are exploring the accelerator, or overload, hypothesis, which suggests being overweight or obese is triggering type 1 diabetes in children who are predisposed to it -- and may explain the increase in diagnoses during the last decade.
But there is no clear link between obesity and type 1 diabetes, or other explanation for increased incidence of the condition, which researchers say is most likely influenced by environment, rather than sudden widespread changes to genetics.
"These findings lead to many more questions," Dr. Barbara Linder, senior advisor for childhood diabetes research at NIH's National Institute of Diabetes and Digestive and Kidney Diseases, said in a press release.