May 21, 2012 -- Two new studies show the early health risks the ever-enlarging number of obese U.S. teens face, from diabetes to heart damage.
According to new research from the CDC, many overweight and obese teens who appear otherwise healthy already have heart disease risk factors such as high blood pressure. As many as 60% of obese teens are affected.
Many obese teens also have troubling physical changes in their heart, such as thicker heart muscle walls, according to another new study.
Even some teens who are normal weight have some heart disease risk factors, the CDC team found.
"Parents should be concerned and aware of these findings," says researcher Ashleigh L. May, PhD, an epidemiologist at the CDC.
"The main story here is that in addition to obesity, you need to be aware of these other potential risk factors for cardiovascular disease, that these risk factors are present relatively early," May tells WebMD.
The CDC study is published in Pediatrics, while the heart muscle findings are being presented today at the Heart Failure Congress 2012 in Belgrade, Serbia.
The CDC researchers looked at nearly 3,400 teens and pre-teens, ages 12 to 19. They looked at 1999-2000 data and 2007-2008 data from a large national health study called NHANES (National Health and Nutrition Examination Survey).
As body mass index (BMI) rose, so did the risk factors, May tells WebMD.
"As weight increases, we observed an increase in the percentage of adolescents who had at least one cardiovascular risk factor," she says.
Among these risk factors are high blood pressure, high cholesterol, and high blood sugar.
The researchers found at least one heart disease risk factor present in:
60% of obese teens
50% of overweight teens
37% of healthy-weight teens
May can't say why the healthy-weight teens had risk factors. "It could be poor diet, or lack of physical activity; we can't say for sure," she says.
The percent of teens who were found to have high blood pressure or be in danger of getting it didn't change between the two time periods.
Neither did the number who had high LDL or ''bad" cholesterol.
However, those who had diabetes or were in danger of getting it increased from 9% in 1999-2000 to 23% in the 2007-2008 survey.
However, May's team says this result "should be interpreted with caution," as they identified these youths by a one-time test for blood sugar levels. This single measure may not be totally dependable in children, May says.
Even so, the findings should be a call to action, the researchers say.
"Parents should be encouraging healthy lifestyles and should also be aware that these cardiovascular risk factors are present during adolescence," May says.