Increased time spent watching television is associated with higher mortality in general and increased cardiovascular disease–related death in particular, according to findings from an Australian population-based cohort study.
Each hour spent in front of the television daily was associated with an 18% increased risk of cardiovascular disease–related death and an 11% increase of death from all causes, wrote David Dunstan, Ph.D., of the Baker IDI Heart and Diabetes Institute in Melbourne, Australia, and colleagues.
Participants who watched television 4 or more hours daily had an 80% increased risk for cardiovascular disease–related death and a 46% higher risk of death from all causes when compared with those who watched less than 2 hours a day (DOI:10.1161/CirculationAHA.109.894824
The risks “were independent of traditional risk factors such as smoking, blood pressure, cholesterol, and diet, as well as leisure-time exercise and waist circumference,” Dr. Dunstan and his colleagues noted.
Investigators examined the relationship between television viewing time and mortality in a national population-based cohort from the Australian Diabetes, Obesity and Lifestyle Study. The participants were enrolled during 1999–2000 and followed through 2006.
A total of 8,800 participants (3,846 men and 4,954 women, a mean age of 50 years) met all inclusion criteria for the analysis. Everyone had undergone testing for glucose levels, fasting serum triglycerides, total cholesterol, and HDL cholesterol. Those with a history of cardiovascular disease or stroke were excluded.
At enrollment, participants reported television-viewing habits for the previous 7 days and were grouped into one of three categories: less than 2 hours daily, between 2 and 4 hours, and more than 4 hours daily. Timeframes when the television was on, but participants were otherwise engaged, did not count.
During the median follow-up of 6.6 years, 284 deaths occurred; 87 were due to cardiovascular disease.
The study was limited by the fact that it assessed a single behavior. However, time spent watching television “has been shown to be a reasonable proxy measure of an overall sedentary behavior pattern,” the authors stated.
The study was funded by the National Health and Medical Research Council and received in-kind support from the Australian Institute of Health and Welfare. The authors reported having no conflicts of interest.
Each hour spent watching TV was linked to an 18% higher risk of cardiovascular disease–related death.
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