Though the exact causes are unknown, the obesity epidemic is one likely culprit.

In the U.S., the number of adults newly diagnosed with diabetes has more than tripled over the last thirty years, from 500,000 in 1980 to more than 1.5 million in 2011, according to the U.S. Centers for Disease Control and Prevention (CDC).

Until now, there’s been very little information on the incidence of diabetes among American youth. But a newly published study in the Journal of the American Medical Association (JAMA) shows that the trend is nearly as dramatic for children and teens.

Between 2001 and 2009, the number of U.S. youths living with type 1 diabetes increased by at least 21 percent, according to researchers at the Colorado School of Public Health and the University of North Carolina at Chapel Hill. That increase was seen across the board, irrespective of gender, race, age, or ethnic group.

The number of young people living with type 2 diabetes increased as well. The rate of children and teens with type 2 diabetes jumped by about 30 percent over a period of just 8 years. The increase was seen in both boys and girls, younger and older children, and among white, black, and Hispanic youths, the researchers said.

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Researchers don’t know precisely why diabetes rates are spiking. But because of the jump in the number of cases, it’s likely that something significant has changed in our environment, says study co-author Dr. Dana Dabelea, the associate dean for faculty at the Colorado School of Public Health.

“Our study now provides … data documenting a serious increase in the prevalence of both type 1 diabetes and type 2 diabetes. Whether that meets the definition of ‘epidemic’ is now more or less semantics,” Dabelea says.

Type 2 diabetes can be the result of poor diet and obesity, though genes and family history also play a part.

“Several reasons for the increasing type 2 diabetes prevalence are possible. Most likely are the obesity epidemic, but also the long term effects of diabetes and obesity during pregnancy, which has also increased over time,” Dabelea says.

The study looked at more than three million patients from centers in California, Colorado, Ohio, South Carolina, and Washington, as well as Native American reservations in New Mexico and Arizona.

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“The increases reported by our study should draw attention to the seriousness of the public health impact of pediatric diabetes,” Dabelea adds. “At the individual level, every new case at a young age means a lifetime burden of difficult and costly treatment and higher risk of early, serious complications.”

To get a full picture of the impact of diabetes in the U.S., further large studies are needed, Dabelea says. Just as important are complimentary programs that might help prevent diabetes. “Only by doing so we will understand the impact of potential changes in the environment in which U.S. children are born and raised on the risk of diabetes,” she says.

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