The findings underscore the message that "it's never too early to think about your heart health."

Indicators of cardiovascular health first begin to worsen around the time most US children are making the transition from elementary to middle school, data from Massachusetts suggest.

The estimated mean age when CV health scores -- derived from the Life's Essential 8 tool from the American Heart Association (AHA) -- began their slide was 10.1 years for males and 10.0 for females, with boys seeing both a larger improvement in CV health before that point and a speedier decline after that age compared with girls.

The results, published online last week in JAMA Cardiology, also point to the impact of social determinants of health, like race/ethnicity, maternal education, and household income, on trajectories early in life.

Data like these are "important to inform primordial prevention strategies" to stave off cardiovascular disease, lead author Izzuddin Aris, PhD (Harvard Medical School and Harvard Pilgrim Health Care Institute, Boston, MA), told TCTMD. "We were able to find a really critical period in the life course where cardiovascular health starts to decline, and I think this will move the needle by informing potential preventive or interventional strategies moving forward," Aris said.

As for why cardiovascular health begins to worsen around age 10, he pointed to behavioral changes that affect diet, physical activity, and sleep duration that typically occur at this time of life, adding that adolescents may start to smoke as well.

Sociodemographic Factors At Play

The AHA introduced Life's Simple 7 in 2010 as way to assess an individual's overall CV health status based on seven parameters: nicotine exposure, diet, physical activity, body mass index (BMI), blood pressure, glucose, and cholesterol. In 2022, the tool was updated to Life's Essential 8 with the addition of sleep duration as a metric.

"Importantly, this construct provides guidance on primordial prevention of CVD and holds promise to enhance CV health assessment across the life course, especially during early life," Aris et al write.

In the current study, the investigators used Life's Essential 8 to track CV health from early childhood through adolescence within Project Viva, an ongoing prospective prebirth cohort study conducted at a large multispecialty group practice in eastern Massachusetts. The analysis included 1,523 children (51.4% male) born to women who were pregnant and enrolled in the study between April 1999 and November 2002.

All participants had information on at least three of the Life's Essential 8 metrics available in early childhood (median age 3.2 years) and at least four metrics in mid-childhood (median age 7.7 years), early adolescence (median age 13.0 years), or late adolescence (median age 17.5 years).

Mean CV health score, which ranges from 0 (worst) to 100 (best), was 82.6 in early childhood, 84.1 in mid-childhood, 82.0 in early adolescence, and 73.8 in late adolescence. The drop off around age 10 was mostly driven by changes in behavioral factors, including sleep, physical activity, and diet.

The researchers identified some small differences in CV health trajectories across sociodemographic groups. For instance, health status tended to be worse throughout early life among non-Hispanic Black and Hispanic children versus their non-Hispanic white peers and among children born to mothers with lower levels of education and lower household incomes.

The study "highlights this potential early influence of important structural factors that are linked to socioeconomic status, as well as race and ethnicity, that could actually contribute to future cardiovascular health disparities," Aris said.

'It's Never Too Early'

In an accompanying editorial, Natalie Cameron, MD, MPH, and Norrina Allen, PhD, MPH (both from Northwestern University Feinberg School of Medicine, Chicago, IL), call this study "an important addition to the growing body of literature demonstrating population-level declines in CV health beginning early in the life course." This is the case despite it being limited in generalizability, they say, since all participants lived in eastern Massachusetts and most were non-Hispanic white with mothers who had a least a college education.

Cameron and Allen point to a 2016 scientific statement from the AHA for strategies for promoting cardiovascular health in children, which include "screening and counseling for diet quality at healthcare visits, initiating community-based enhancements to improve access to healthy foods and areas for play, implementing school-based programs for physical activity promotion, and expanding prevention campaigns for smoking cessation."

Speaking with TCTMD, Cameron underscored the importance of schools in this effort. "We need to make sure our schools are supporting kids for their cardiovascular health," she said, noting that some states have pushed start times later to allow for adequate sleep.

She said she wasn't surprised to see that CV started to decline around age 10 since prior research has shown these types of trends early in life, although further studies are needed to delve into why it's happening. "We can hypothesize about changes in school and academic pressure and social pressure and social media and all these things, but they didn't really have data in this study to look into that," Cameron said.

Also, more research is needed to understand why certain demographic groups are faring worse than others, which will help "to engage with communities and design the interventions that best fit their needs," she said.

But for now, Cameron said, the message is: "It's never too early to think about your heart health. I think we tend to wait until something goes wrong, until you're older and you develop high blood pressure, or God forbid, have a heart attack. But promoting cardiovascular health early and staying healthy throughout the life course and early in the life course is really important."