Too much sitting after work harms heart: study
Spending more than two hours a day of leisure time in front of a TV or computer screen may increase the risk of heart disease and shorten life, a new study suggests.
British researchers compared the effects of sitting for different lengths of time during leisure hours, outside of work.
People who spent more than four hours each day watching TV, using a computer or playing video games were about twice as likely to suffer a major cardiac event, Emmanuel Stamatakis of University College London's department of epidemiology and public health and his co-authors reported in Monday's issue of the Journal of the American College of Cardiology.
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Stamatakis is calling for public health guidelines to warn people of the risks of being physically inactive during their down time.
The warnings are important, "especially as a majority of working age adults spend long periods being inactive while commuting or being slouched over a desk or computer," the study's authors wrote.
The study focused on 4,512 adults who took part in a survey of Scottish households. Participants said how much time they spent watching TV, DVDs, using computers and playing video games.
There was a 1.52 times higher risk of cardiovascular events such as heart attack, stroke or heart failure among participants reporting four or more hours of screen time compared with those who said they got less than two hours.
During more than four years of follow-up, 325 of the subjects died and 215 had a cardiovascular event, the researchers reported.
The study is the first time researchers have examined the association between screen time and cardiovascular health in such detail, the authors said.
Inflammation and metabolism
The researchers took into account traditional risk factors such as smoking, hypertension, body mass index, social class and exercise.
Stamatakis's team did find an association between levels of inflammation and cholesterol in sedentary people, which they say partly explains about one-forth of the relationship between sitting and heart health.
The study helps doctors to understand the significant role that a sedentary lifestyle has on heart disease, Dr. Suzanne Steinbaum, a preventive cardiologist at Lenox Hill Hospital in New York City and a spokeswoman for the American Heart Association, told the paper to HealthDay.
Steinbaum suggested that people avoid sitting when they don't have to during leisure time and try to get moving instead.