The findings establish a critical foundation for understanding how cardiovascular health develops - and potentially deteriorates - during childhood. Perhaps most importantly, the study highlights that heart health isn't just an adult concern - it's a lifetime journey that begins in childhood. The choices and habits formed during these early years can set the stage for cardiovascular health throughout life.
The researchers used data from Project Viva, a pre-birth cohort study in eastern Massachusetts that began recruiting pregnant women between 1999 and 2002. They followed 1,523 children, collecting data at four key life stages: early childhood (median age 3.2 years), middle childhood (median age 7.7 years), early adolescence (median age 13.0 years), and late adolescence (median age 17.5 years).
To be included in the study, children needed to have information on at least 3 cardiovascular health metrics in early childhood or at least 4 metrics in the later stages. In early childhood, researchers assessed 6 metrics (diet, smoking exposure, physical activity, sleep duration, BMI, and blood pressure), expanding to 8 metrics in later stages by adding blood glucose and cholesterol measurements.
The study identified a clear inflection point around age 10 when cardiovascular health began to decline across all demographic groups. Boys showed both faster improvement before this point and a steeper decline afterward compared to girls. The mean age of inflection was 10.1 years for male children and 10.0 years for female children.
Children from lower-income families and those whose mothers had less education consistently showed lower cardiovascular health scores. Importantly, the decline in health was primarily driven by behavioral factors rather than biological ones, suggesting that lifestyle interventions could be particularly effective.
Researchers relied partly on self-reported or parent-reported information for factors like physical activity and sleep, which might not be as accurate as objective measurements. The participant group was primarily from eastern Massachusetts and had higher overall cardiovascular health than the general U.S. child population, potentially limiting the findings' broader applicability. Additionally, about 28% of the original cohort was excluded from the analysis, and these children were more likely to be from lower socioeconomic status families.
The study provides crucial evidence that cardiovascular health interventions should begin early in life, with particular attention to the period around age 10. The findings suggest that focusing on behavioral factors like diet, physical activity, and sleep might be more effective than focusing solely on biological factors. The research also highlights the need to address socioeconomic and racial disparities in childhood cardiovascular health, particularly through structural changes that affect access to healthy foods and safe spaces for physical activity.
Project Viva is supported by grants from the National Institutes of Health. The current study received additional funding from the National Institutes of Health and the American Heart Association. The researchers reported no conflicts of interest.
This research was published in JAMA Cardiology on December 18, 2024. The paper, titled "Trajectory of Cardiovascular Health Across Childhood and Adolescence," can be found using its Digital Object Identifier (DOI): 10.1001/jamacardio.2024.4022. JAMA Cardiology is part of the JAMA Network family of medical journals, which are peer-reviewed publications known for their rigorous scientific standards.