WASHINGTON, D.C, Sept. 17, 2015 -- Long before they have symptoms, blood tests in obese African-American teens, especially girls, reveal immune system changes linked to greater cardiovascular disease risk, according to a study presented at the American Heart Association's 2015 High Blood Pressure Conference.
"Obesity in the formative years is already priming the system to develop cardiovascular disease later in life," said Carmen De Miguel, Ph.D., study lead researcher and a postdoctoral scholar at the University of Alabama at Birmingham.
There is substantial evidence that the immune system is involved in the development of cardiovascular disease, with changes in immune cells in the blood appearing years before people develop high blood pressure, type 2 diabetes, or cardiovascular diseases. The new study shows that obesity-related immune cell changes appear early - particularly in African-American girls.
Researchers conducted blood tests on about 100 white and African American public school students between the ages of 14 and 20 in Augusta, Georgia. Obese teens were over the 95th percentile for weight, while lean teens were below the 60th percentile of weight.
To determine obesity's effect on inflammation, researchers compared levels of T-cells and their activation status among lean and obese children by race and gender. Activated T-cells are a sign of inflammation. Researchers found:
- White teenagers displayed less systemic inflammation (marked by smaller numbers of T-cells in the blood) in response to obesity than black teens.
- Obese black teenage girls had higher levels of activated T cells compared to obese black teenage boys.
"We think that the fact that the girls do not decrease the numbers of activated T cells could be important in explaining the high risk that black females have of developing cardiovascular disease later in life," De Miguel said.
Since changes in the immune system appear years before symptoms of heart disease, De Miguel suggests that health professionals could use blood tests to identify teens who are at high risk of developing cardiovascular disease in the future.
"This could allow for preventive therapies and help changing exercise and diet habits to make the teen less prone to heart disease in adulthood," De Miguel said.
Co-authors are Xiaojing Xu, Ph.D.; Yue Pan, B.S.; Dennis Ownby, M.D.; Xiaoling Wang, M.D., Ph.D.; and Jennifer S. Pollock, Ph.D. Author disclosures are on the abstract.
The American Heart Association; National Heart, Lung, and Blood Institute; the University of Alabama at Birmingham and Georgia Regents University funded the study.
Researcher photo and blood pressure images are located in the right column of this release link http://newsroom.
Follow #HBPR15 on Twitter for conference news and updates.
For high blood pressure tools and information visit heart.org/hbp.
For the latest heart and stroke news, follow us on Twitter @HeartNews.
Statements and conclusions of study authors that are presented at American Heart Association scientific meetings are solely those of the study authors and do not necessarily reflect association policy or position. The association makes no representation or warranty as to their accuracy or reliability. The association receives funding primarily from individuals; foundations and corporations (including pharmaceutical, device manufacturers and other companies) also make donations and fund specific association programs and events. The association has strict policies to prevent these relationships from influencing the science content. Revenues from pharmaceutical and device corporations are available at http://www.