A snapshot of cardiovascular health in today's youth bears no good news for their adult years or the future of the country's public health, unless there are immediate and sweeping social and cultural changes, according to the American Heart Association.

The AHA's examination of a sample representing more than 33 million U.S. adolescents showed that less than 1% had an ideal diet score. Less than half of adolescents achieved an ideal score in five or more of the seven cardiovascular health components measured in the study. None had ideal levels in all seven categories.

"Because individual-level interventions are often ineffective because of limited physician effort, limited preventive care reimbursement, and unsupportive environmental factors, broad social and cultural changes that infiltrate the entire population will be necessary to evoke changes in youth behaviors that will favorably influence cardiovascular health," wrote the authors, led by Christina M. Shay, Ph.D., University of Oklahoma Health Sciences Center, Oklahoma City.

"The support of parents, health care professionals, educators, scientists, and legislators will be required to ignite a social movement influential enough to facilitate the change needed to improve the current status of cardiovascular health in children and adolescents and prevent atherosclerosis," they continued. (Circulation 2013 April 2 [doi: 10.1161/CIRCULATIONAHA.113.001559]).

The study follows a 2012 analysis of cardiovascular health in U.S. adults (Circulation 2012;125:45-56).

The AHA recently released the 2020 Strategic Impact Goals to help prevent cardiovascular disease and maintain cardiovascular health from youth throughout adulthood (Circulation 2010;121:586-613). The two analyses provide a baseline to measure progress toward that goal.

AHA defines cardiovascular health by seven health behaviors and factors: no smoking, body mass index, dietary intake, physical activity, blood pressure, blood glucose, and total cholesterol. It quantifies each category with a composite score for CV health with 0 for poor, 1 for intermediate, and 2 for ideal.

The authors examined components of cardiovascular health in 4,673 participants between ages 12 and 19 years from the 2005 to 2010 National Health and Nutrition Examination Surveys (NHANES). The sample group provides an estimated representation of 33.2 million U.S. adolescents.

The sample was well-balanced by sex. The majority of participants were non-Hispanic white (60%), and more than half reported an annual household income of $45,000 or more.

The examination of the data showed that fewer than half of adolescents exhibited five or more of AHA's ideal cardiovascular health components (45% males and 50% females). Of the maximum score of 14, non-Hispanic white males and females had the highest median Cardiovascular Health Score (9.3 and 9.4 respectively). Mexican American meals and non-Hispanic black females had the lowest score (8.4 and 8.7 respectively).

Females, especially non-Hispanic whites, had a lower prevalence of ideal total cholesterol (65% females v. 72% males), and ideal physical activity (44% v. 67%).

Nearly two-third of the adolescents had an ideal body mass index (66% males and 67% females), but non-Hispanic black females and Mexican American males were more overweight or obese compared with non-Hispanic whites.

Also, nearly two-thirds had ideal smoking status (67% males and 70% females). Ideal smoking status was the most prevalent CV health behavior in all sex and race/ethnicity groups, especially among non-Hispanic blacks.

Ideal blood pressure was the most favorable cardiovascular health factor (78% males and 90% females.)

Meanwhile, females had a higher prevalence of ideal blood glucose (89% v. 74% males). Non-Hispanic blacks had the highest prevalence of ideal fasting blood glucose compared with non-Hispanic whites and Mexican Americans. Roughly a quarter of all adolescents had intermediate fasting blood glucose levels.

"These current estimates of an unacceptably high prevalence of poor and intermediate components of cardiovascular health among U.S. adolescents are an important reminder of the substantial evidence that cardiovascular risk factors and behaviors associated with the development of adult atherosclerosis frequently develop early in life," the authors wrote.

"When these current estimates of the prevalence of cardiovascular health components in the U.S. adolescent population are considered, it can be seen that significant clinical and public health interventions will be required to maintain the valuable asset of cardiovascular health from childhood throughout the life span of the population, particularly among minority populations," they added.

The study has several limitations, according to the authors. Although the data are nationally representative, they are cross-sectional and don't represent temporal changes at an individual level. The data are also insufficient to obtain a confident diagnosis of clinical disease and as a result may underestimate ideal levels of CV health components. Also, the Cardiovascular Health Score does not weight the influence of each individual component, "and should be interpreted in light of this limitation," the authors noted.

They also noted that it is important to consider the fluctuations in health factors - such as increases in total cholesterol levels - that occur naturally during puberty and adolescence. Since NHANES is a cross-section, it does not allow for serial evaluation of CV factors, which could as a result increase the likelihood of misclassification.

The study was supported in part by a grant from the National Heart, Lung, and Blood Institute. None of the authors reported any disclosures except for Dr. Stephen R. Daniels who was the chair of the Data Safety and Monitoring Board for Merck Pharmaceuticals.

nmiller@frontlinemedcom.com

On Twitter @naseemsmiller