The time that children spend inactive, using their electronic devices or watching television, for example, could have very negative consequences for their health, since a new study presented at the Congress of the European Society of Cardiology ESC 2023 has found that the cumulative sedentary lifestyle from childhood to adulthood it is associated with heart damage that can cause a heart attack or stroke later, even in people with normal weight and blood pressure levels.
“All those screen hours in the young add up to a heavier heart, which we know from studies in adults increases the likelihood of heart attack and stroke,” said Dr. Andrew Agbaje of Eastern University. Finland, in Kuopio, Finland, and author of the study. “Children and adolescents need to move more to protect their long-term health.”
Impact of accumulated downtime on the heart
This is the first study that has evaluated the cumulative effect of sedentary time measured with smart watches in young people and heart damage later in life. It was conducted as part of the Children of the 1990s study, which began in 1990/1991 and is one of the largest cohorts in the world with lifestyle measurements from birth.
“Our study indicates that the accumulation of inactive time is related to cardiac damage independent of body weight and blood pressure”
At age 11, the boys wore an activity tracker smartwatch for seven days. This was repeated at age 15 and again at age 24. Left ventricular heart weight was assessed by echocardiography at 17 and 24 years and reported in grams relative to height (g/m 2.7).
The researchers analyzed the association between sedentary time between the ages of 11 and 24 and cardiac measurements between the ages of 17 and 24 after adjusting for factors that could influence the relationship, such as age, gender, blood pressure, body fat, smoking, physical activity and socioeconomic status.
The study involved 766 children (55% girls and 45% boys). At age 11, the children were sedentary for an average of 362 minutes per day, increasing to 474 minutes per day in adolescence (15 years) and 531 minutes per day in youth (24 years). This means that sedentary time increased by a mean of 169 minutes (2.8 hours) daily between childhood and early adulthood.
Each one-minute increase in sedentary time between ages 11 and 24 years was associated with a 0.004 g/m2,7 increase in left ventricular mass between ages 17 and 24 years. When multiplied by 169 minutes of additional inactivity, this equates to a daily increase of 0.7 g/m2,7 the equivalent of a 3-gram increase in left ventricular mass between echocardiography measurements with an average height gain . An earlier study in adults found that a similar increase in left ventricular mass (1 g/m2,7) over a seven-year period was associated with a twice the risk of heart disease, stroke, and death.
Dr. Agbaje said: “The children were sedentary for more than six hours a day and this increased by nearly three hours a day by the time they reached adulthood. Our study indicates that the accumulation of inactive time is related to cardiac damage independent of body weight and blood pressure. Parents should encourage children and adolescents to move more by taking them for walks and limiting the time they spend on social media and video games. As Martin Luther King Jr. once said: ‘If you can’t fly, run. If you can not run, walk. If you can not walk, crawl. But of course, keep moving.’”