Extended Sedentary Time in Children Associated with Heart Damage in Adulthood

Andrew Agbaje, MD, MPH

Credit: LinkedIn

Prolonged sedentary time in growth from childhood through young adulthood is associated with progressive left ventricular structural remodeling, setting the stage for heart attack and stroke later in life, according to new research.¹

The data presented at the European Society of Cardiology (ESC) Congress 2023 showed sedentary time accumulated in this period was associated with heart damage, even in individuals with normal weight and blood pressure.

“All those hours of screen time in young people add up to a heavier heart, which we know from studies in adults raises the likelihood of heart attack and stroke,” said study author Andrew Agbaje, MD, MPH, of the University of Eastern Finland, in a statement.² “Children and teenagers need to move more to protect their long-term health.”

Sedentary time and behavior measured in questionnaires have been associated with poor cardiometabolic profiles in the pediatric population. Objectively measured sedentary time, however, has not been associated with poor cardiometabolic health in a consistent manner.

Investigators identified a paucity of evidence of the cumulative effect of time spent sedentary with cardiac structural changes in youth. As a result, the investigative team measured the cumulative effect of smartwatch-assessed sedentary time in youth and cardiac damage in later life. Children were recruited from the Avon Longitudinal Study of Parents and Children (ALSPAC), a United Kingdom birth cohort.

Study participants wore an ActiGraph accelerometer for a 4-7-day period at the 11-year clinic visit; this was repeated in clinic visits at 15 years of age and at 24 years of age. Repeated echocardiography measured left ventricular mass indexed for height (g/m^2.7) and relative wall thickness were both measured at baseline and follow-up.

Investigators examined multivariable-adjusted associations between sedentary time (11-24 years) and heart measurements (17-24 years) using generalized linear mixed-effect models. Adjustments were made for factors that could influence this relationship, including sex, age, and other time-varying covariates, including blood pressure, body fat, smoking, physical activity, and socioeconomic status.

A total of 766 children were included in the study, of whom 55% were female and 45% were male. Upon analysis, male children spent an average of 360, 467, and 527 minutes per day sedentary at ages 11, 15, and 24 years, respectively. Female children spent 364, 481, and 535 minutes per day sedentary at ages 11, 15, and 24 years, respectively.

Together, investigators found sedentary time increased by an average of 169 minutes per day between childhood and young adulthood. Left ventricular mass (g/m^2.7) was significantly higher among male children, with an average difference of ~4g/m^2.7 at both ages 17 and 24 years.

The fully adjusted model revealed a one-minute increase in sedentary time from ages 11 - 24 years was associated with an increase of 0.004 g/m^2.7 (95% CI, 0.001 - 0.006; P = .002) in left ventricular mass between ages 17 – 24 in the total cohort. For female patients, the increase was 0.009 g/m^2.7 (95% CI, 0.005 - 0.012; P <.0001).

No statistically significant longitudinal association between cumulative sedentary time and changes in retinal wall thickness in the total cohort, male, and female patients was identified by the analysis.

After multiplying by 169 minutes of additional inactivity, the analysis showed a daily increase of 0.7 g/m^2.7, the equivalent of a 3-gram increase in left ventricular mass between echocardiography measurements at the average height gain.

As the accumulation of inactive time is related to heart damage, regardless of body weight and blood pressure, investigators stressed the need for children to move more and reduce sedentary time.

“Parents should encourage children and teenagers to move more by taking them out for a walk and limiting time spent on social media and video games,” Agbaje said.² “As Martin Luther King Jr. once said, ‘If you can’t fly, run. If you can’t run, walk. If you can’t walk, crawl. But by all means, keep moving.”

References

1. Agbaje AO. Cumulative accelerometer-based sedentary time from childhood through young adulthood with progressive left ventricular remodeling in British youth: a 13-year longitudinal study. Poster at the European Society of Cardiology (ESC) Congress 2023. Amsterdam, the Netherlands. August 25-August 28.
2. Sedentary time in children linked with heart damage in young adulthood. European Society of Cardiology. August 23, 2023. Accessed August 24, 2023. https://www.escardio.org/The-ESC/Press-Office/Press-releases/Sedentary-time-in-children-linked-with-heart-damage-in-young-adulthood.