Among adults, higher left ventricular mass (LVM) is a strong predictor of cardiovascular mortality, and regressive changes in LVM among adults have been associated with low rates of clinical events.
A new study from the Universities of Bristol and Exeter and the University of Eastern Finland, which includes 1682 children and adolescents, aims to examine the effect of sedentary time (ST), light-intensity physical activity (LPA), moderate-to-vigorous-intensity physical activity (MVPA) on changes in cardiac structural and functional properties during growth until young adulthood.
The study suggests that increased sedentary time from childhood causes progressing heart enlargement. But, light physical activity could reduce the risk.
Scientists followed up with the research participants from ages 11 to 24. By young adulthood, they were engaging in sedentary activities on average for nine hours a day, up from six hours at baseline. Growing heart enlargement was linked to this rise in sedentary time, which accounted for 40% of the total increase in heart mass across the seven-year growth period from adolescence to young adulthood. Regardless of obesity or high blood pressure, being sedentary increases heart mass.
Conversely, during the follow-up, three to four hours a day of light physical activity (LPA) decreased the rise in cardiac mass by 49 percent. A higher LPA was linked to improved heart health as well.
Engaging in moderate-to-vigorous physical activity (MVPA) has been shown to cause a small, essentially physiological 5% increase in heart size.
Excessive sedentariness has been associated in the same population with high insulin, fat obesity, dyslipidemia, elevated inflammation, and stiffness in the arteries. LPA has shown to be a successful strategy for reducing the negative consequences of childhood sedentariness. To date, however, no research worldwide has investigated the possibility of reversing the increase in heart mass resulting from childhood exposure to long-term levels of LPA. This is due to the rarity of repeated echocardiography evaluations of the heart in a sizable group of young, healthy individuals.
This new study is the largest and the longest follow-up accelerometer-measured movement behavior and repeated echocardiography study in the world. The subjects obtained echocardiogram measurements of the anatomy and function of their hearts at ages 17 and 24 and accelerometer devices worn on their waists for 4-6 days at ages 11, 15, and 24.
Additionally, multiple measurements of their fasting blood samples were made for triglycerides, glucose, insulin, high-sensitivity C-reactive protein, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol. The studies considered blood pressure, heart rate, smoking status, socioeconomic status, and family history of cardiovascular disease, and dual-energy X-ray absorptiometry evaluated fat mass and lean mass.
Andrew Agbaje, an award-winning physician and associate professor (docent) of clinical epidemiology and child health at the University of Eastern Finland, said, “There is growing evidence that childhood sedentariness is a health threat that needs to be taken seriously. There must be a paradigm shift in how we view childhood sedentariness, as the mounting evidence points at a ticking time bomb.”
“LPA is an effective antidote to sedentariness. It is easy to accumulate three to four hours of LPA daily. Examples of LPA are outdoor games, playing in the playground, walking a dog, running errands for parents, walking and biking to the shopping mall or to school, taking a stroll in the park, playing in the forest, gardening, casual basketball, soccer, floorball, golf, frisbee, etc. We can encourage children and adolescents to participate in LPA daily for better cardiovascular health.”
Journal Reference:
- Andrew O Agbaje. Accelerometer-based sedentary time and physical activity from childhood through young adulthood with progressive cardiac changes: a 13-year longitudinal study. European Journal of Preventive Cardiology. DOI: 10.1093/eurjpc/zwae129