Research presented at the World Heart Federation's World Congress of Cardiology today suggests that children who spend over 2 hours in front of a TV, computer or video games each day have a significantly increased chance of having high blood pressure.
The researchers, led by Dr. Gilles Paradis, of McGill University in Canada, say such children have over a 2.5-fold increase in odds of having high blood pressure (BP), while children with a low level of fitness had odds 3.4 times higher, compared with children with a high level of fitness.
They add that high BP during childhood is linked to early markers of cardiovascular disease (CVD).
According to the World Health Organization (WHO), around 17.3 million people around the world died from CVD in 2008, and by 2030, more than 23 million people will die annually from such diseases.
Children who have high BP will likely have it as adults unless treatment or interventions are taken. In children, high BP is defined as blood pressure that is the same or higher than 95% of children who are the same sex, age and height.
However, researchers from the Mayo Clinic in Rochester, MN, note that there is not a simple target blood pressure reading for children, "because what's considered normal blood pressure changes as children grow."
Higher screen time increases the risk of high blood pressure in youths, researchers say.
While high BP in children under 10 years of age is typically due to another medical condition, it can develop for the same reasons that it does in adults: being overweight, eating poorly and not exercising.
The researchers add that physical inactivity is strongly linked to CVD and is the fourth leading cause of mortality worldwide, responsible for around 3.2 million deaths a year.
Physical activity protects from CVD
To further investigate factors that could contribute to high BP in children, this latest study measured the relationship between blood pressure and inactivity, sedentary behaviors and fitness in 630 children between the ages of 8 and 10 who were at high risk of obesity.
Fast facts about heart health
- Heart attack and stroke risk increase with tobacco use, unhealthy diet and physical inactivity
- 30 minutes of daily physical activity prevents heart attacks and strokes
- Limiting salt intake and eating at least five servings of fruit/veg each day also prevents heart attacks and strokes.
The team took five blood pressure readings in succession and analyzed physical activity of the subjects for 1 week with a device that measures movement, called an accelerometer.
The children also completed questionnaires regarding their physical inactivity from watching TV, using a computer, playing video games, studying and reading.
Then, the researchers gauged their fitness through an exercise test on a stationary bike, and they measured their height, weight and sexual maturation.
Socioeconomic background was also considered, and the team recorded the children who had parents with a history of BP, in order to adjust the results.
Results revealed that children who engaged in more than 2 hours of screen time daily had a 2.7-fold increase in odds of elevated diastolic blood pressure, and the team notes this association was more noticeable in overweight and obese children.
Commenting on the findings, Dr. Paradis says:
"The study also emphasized that being physically active protects children from the risk of CVD. Physical activity prolongs lives regardless of inherited factors and protects against a vast number of health problems including cardiovascular disease."
Their study adds to other evidence suggesting it may be possible to reduce the number of deaths due to CVD if children are more physically active, the team notes.
Srinath Reddy, president of the World Heart Federation and the Public Health Foundation of India says high BP "has earned its reputation as the silent killer and combating its early onset in children is absolutely vital."
To reduce "this risk of mortality in future generations," Reddy adds, we need to do more "to combat sedentary behaviors developing at a young age."
The WHO recommend that children engage in 60 minutes of moderate to vigorous activity each day, while adults should complete 150 minutes of moderate-intensity activity each week.
Medical News Today recently reported on a study that suggested individuals who are obese by age 25 are more likely to be severely obese after the age of 35.