Sitting in front of a TV or computer for long periods can raise the risk of cardiovascular disease and death, reported investigators recently in the Journal of the American College of Cardiology. The risk does not appear to be offset by physical activity.
Included in the study were 4512 participants in the 2003 Scottish Health Survey who were age 35 years or older. During an average 4.3 years of follow-up, a total of 325 all-cause deaths and 215 cardiac events occurred.
Compared with persons who spent less than 2 leisure hours a day watching TV or using a computer, those who devoted more than 4 hours to these activities had a 48% increased risk of all-cause mortality. Persons in the study who spent 2 or more leisure hours in front of a screen had an approximately 125% increase in risk of cardiovascular events. These associations were independent of traditional risk factors, such as smoking and hypertension.
Inflammatory and metabolic risk factors are partly responsible for the association between screen time and cardiovascular events, noted the researchers. C-reactive protein levels were about 2 times higher in persons who spent more than 4 hours of leisure time per day in front of a TV or computer screen compared with those who spent fewer than 2 hours a day.
"People who spend excessive amounts of time in front of a screen - primarily watching TV - are more likely to die of any cause and suffer heart-related problems," said Emmanuel Stamatakis, PhD, MSc, Department of Epidemiology and Public Health, University College London, United Kingdom. "Our analysis suggests that two or more hours of screen time each day may place someone at greater risk for a cardiac event."