Couch potatoes run risk of cardiovascular disease, new international research confirms.
Although some evidence suggests that prolonged sitting is linked to cardiovascular disease risk factor development regardless of physical activity participation, studies with hard outcomes are scarce.
So a team of British and Australian scientists set out to examine the independent relationships of television viewing or other screen-based entertainment ("screen time") with all-cause mortality and clinically confirmed cardiovascular disease (CVD) events.
A secondary objective was to examine the extent to which metabolic (body mass index, high-density lipoprotein and total cholesterol) and inflammatory (C-reactive protein) markers mediate the relationship between screen time and CVD events.
A population sample of 4,512 (1,945 men) Scottish Health Survey 2003 respondents, aged around 35 years, were followed up to 2007 for all-cause mortality and CVD events (fatal and nonfatal combined).
Assessing the screen time and physical activity of the participants, the researchers found 215 CVD events and 325 any-cause deaths occurred in the study period. Approximately 25% of the association between screen time and CVD events was explained by C-reactive protein, body mass index, and high-density lipoprotein cholesterol, they said.
In their paper, published in the Journal of the American College of Cardiology, the researchers led by Dr. Emmanuel Stamatakis, Department of Epidemiology and Public Health, University College London, concluded, "Recreational sitting, as reflected by television/screen viewing time, is related to raised mortality and CVD risk regardless of physical activity participation. Inflammatory and metabolic risk factors partly explain this relationship."