New Danish research links extra device hours with early heart-health markers in kids and teens
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More recreational screen time in children and teens was tied to higher cardiometabolic risk think higher blood pressure, less-favorable cholesterol, and insulin resistance.
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The association was stronger among youth who got less sleep suggesting that screen use may affect heart health in part by stealing sleep.
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Each extra hour of screen time per day wasnt dramatic on its own, but when you add multiple hours, it adds up to a measurable shift in risk.
In a world where kids and teens are increasingly spending hours on phones, tablets, gaming consoles and TVs, its worth asking: what all that screen time especially the unstructured, recreational kind might be doing to their bodies?
According to a new study from Denmark published in the Journal of the American Heart Association, more screen time among younger people may be tied to signs of elevated risk for heart and metabolic trouble later on.
While the findings dont prove cause and effect, they shine a light on how modern screen habits could relate to the groundwork for future heart health.
Limiting discretionary screen time in childhood and adolescence may protect long-term heart and metabolic health, researcher David Horner, M.D., PhD., said in a news release.
Our study provides evidence that this connection starts early and highlights the importance of having balanced daily routines.
The study
Researchers analyzed data from more than 1,000 participants drawn from two long-running Danish cohort studies known as COPSAC Copenhagen Prospective Studies on Asthma in Childhood. The first group was around age 10 (from a 2010 birth-cohort) and the second about age 18 (from a 2000 birth-cohort).
Screen time was self- or parent-reported, covering hours spent watching TV/movies, gaming, or using phones, tablets, or computers for leisure.
To assess risk, the team created a composite cardiometabolic score based on waist circumference, systolic blood pressure, good HDL cholesterol, triglycerides and blood glucose each standardized for age and sex.
They also looked at sleep duration (using data from sensors worn for 14 days), timing of sleep, and used advanced metabolomics to detect a possible biological fingerprint of screen time.
The results
Overall, the study found a clear pattern: the more time kids and teens spent on screens for fun, the more likely they were to show early signs linked to future heart and metabolic problems.
For both age groups 10-year-olds and 18-year-olds extra daily screen time was connected with things like:
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Higher blood pressure
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Less-healthy cholesterol levels
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More insulin resistance, which can be an early sign of issues with blood sugar
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A bigger waist measurement, which can be one marker of health risk
None of these changes were huge on their own, but they added up. For example, every extra hour a day of recreational screen time was tied to a small but noticeable shift toward higher overall health risk. In teens, that shift was a little stronger than in younger kids.
The researchers also found that sleep played a big role. Kids and teens who slept less or went to bed later had an even stronger link between screen time and these health markers. In younger kids, a portion of the screen-time effect could be explained by the fact that screens were cutting into their sleep.
Finally, among the 18-year-olds, more screen time was also tied to a higher predicted risk of developing heart disease later in life. Again, it wasnt dramatic, but it was enough for researchers to pay attention.
What this means for you
If youre parenting or working with young people, the message isnt: ban screens forever.
Rather, its a reminder that heavy recreational screen use may subtly shift the balance of heart-and-metabolic health risk especially when paired with less sleep. Simple, practical steps like encouraging earlier bedtimes, limiting usage in the hour before bed, and introducing non-screen leisure or movement might help.
Because this was an observational study (not a randomized trial), it doesnt prove screen time causes these changes but it does justify conversations about screen habits and sleep as part of healthy routines. Even if each extra hour only nudges risk a little, multiple hours add up. Limiting discretionary screen time and protecting sleep could be one of many small moves that support longer-term heart health in younger generations.
Posted: 2025-11-17 02:24:49















