People who reported spending six or more hours on screens outside of school or work had worse blood pressure, cholesterol and body mass index (BMI) compared with those with more limited screen time, according to a study being presented at the American College of Cardiology's Annual Scientific Session (ACC.26).
Screen time was independently associated with these markers of cardiovascular risk even after accounting for differences in daily physical activity. The findings point to excessive time spent playing video games, watching videos and scrolling social media as an emerging risk factor among young people, researchers said, suggesting that clinicians could assess screen use as an early indicator that patients may be on a trajectory to develop heart disease.
Traditionally, lifestyle counseling focuses mainly on encouraging exercise, but our findings suggest that reducing excessive screen exposure could be an additional and independent target for intervention. This may lead to more nuanced counseling-not only promoting physical activity but also addressing digital behavior patterns, digital wellness and structured limits on prolonged screen use."
Zain Islam, MD, cardiologist at Liaquat University of Medical & Health Sciences and Taqi Medical Center in Hyderabad, Pakistan, and study's lead author
Researchers analyzed heart health markers and daily habits of 382 adults who were about 35 years old, on average, living in Hyderabad and Karachi, two cities in Pakistan. South Asians carry a disproportionately high burden of premature cardiovascular disease, which affects people at younger ages compared with Western populations. Pakistan and other countries in the region have also seen an uptick in screen use among young adults due to rapid urbanization and adoption of digital technologies in homes and workplaces. This study is the first to examine how these changing lifestyle patterns may affect heart health specifically in South Asia and is among the first to focus on screen time as a specific risk factor, according to the researchers.
"What makes this study different is that we looked at screen time as a specific, measurable digital behavior rather than just broadly labeling people as sedentary," Islam said. "While sedentary lifestyle has been studied before, fewer studies have separated screen exposure from general physical inactivity or examined how these two factors interact with each other."
Based on questionnaires, researchers grouped participants according to their screen habits (more or less than six hours on screens outside of school or work per day) and physical activity levels (more or less than 150 minutes of exercise per week). After adjusting for age, sex and baseline clinical characteristics, they found that people spending more than six hours a day on screens had, on average, about 18 mmHg higher systolic blood pressure, over 28 mg/dL higher low-density lipoprotein (LDL) cholesterol and over 3.9 mg/dL lower high-density lipoprotein (HDL) cholesterol compared with those spending less than six hours on screens per day. In addition, these participants had significantly higher BMI, waist circumference and waist-to-height ratio. Higher screen time was also associated with increased cigarette smoking and vaping, with over one-quarter of these participants reporting nicotine use compared with 12% among those with lower screen exposure.
Although these relationships were independent from physical activity levels, researchers also found a synergistic effect between screen use and exercise. High screen time and low physical activity together produced a greater adverse impact on blood pressure and BMI than either factor alone. "In other words, these behaviors don't just add risk independently-they seem to amplify each other when they occur together," Islam said.
Based on the findings, Islam said that clinicians should incorporate screen time alongside traditional lifestyle factors to assess patients' cardiovascular risk and develop tailored interventions that promote both physical activity and healthier screen habits.
As an observational study, researchers said that the research does not establish causality. In addition, screen time was self-reported, and assessments may not consistently differentiate between work-related and recreational use. Additional factors such as diet, sleep or stress may also play a role in the associations that were observed.
Because cultural, environmental and socioeconomic factors differ around the world, Islam said that it is important to continue to study behaviors like screen use in specific populations since findings from one country or region may not translate directly in other places. He said that future studies could include larger multicenter cohorts, objective digital tracking tools rather than self-reporting and longitudinal follow-up to evaluate hard cardiovascular outcomes. Interventional studies testing whether reducing screen time improves cardiometabolic markers would also be an important next step.
Islam will present the study, "Association Between Screen Time, Physical Inactivity, and Cardiovascular Risk Markers in Young Adults: A Prospective Observational Study," on Saturday, March 28, at 2:00 p.m. CT / 19:00 UTC in Posters, Hall E.
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