Binge watching TV may up risk of VTE

People who spend long hours (>4 hours a day) watching television (TV) have an increased risk of developing venous thromboembolism (VTE) than those who seldom watch TV, and this is independent of physical activity, according to a meta-analysis.  

“Our study findings also suggested that being physically active does not eliminate the increased risk of blood clots associated with prolonged TV watching,” said lead author Dr Setor Kunutsor from the University of Bristol, UK.

“If you are going to binge on TV you need to take breaks. You can stand and stretch every 30 minutes or use a stationary bike. And avoid combining TV with unhealthy snacking,” he advised.

The meta-analysis included data of 131,421 participants aged ≥40 years (mean age range, 54–65 years) from three unique population-based prospective cohort studies which assessed the duration of TV viewing by questionnaire. The participants were considered to have prolonged viewing if they spent at least 4 hours a day watching TV, and as never/seldom viewers if they watched <2.5 hours a day. Only studies with at least 1 year of follow-up on incident VTE were included in the meta-analysis.

Over a mean follow-up duration ranging from 5.1 to 19.8 years, there were a total of 964 VTE events. [Eur J Prevent Card 2022;doi:10.1093/eurjpc/zwab220]

Compared with people who seldom or never watch TV (<2.5 hours a day), those who watched TV for >4 hours were 35 percent more likely to develop a VTE (risk ratio, 1.35, 95 percent confidence interval, 1.07–1.70), based on pooled data of the three prospective studies. This was after adjusting for known risk factors of VTE such as age, sex, physical activity, and body mass index.

According to the authors, the quality of the evidence for the meta-analysis was rated as high.

“Prolonged TV viewing involves immobilization which is a risk factor for VTE. This is why people are encouraged to move around after surgery or during a long-haul flight. In addition, when you sit in a cramped position for long periods, blood pools in your extremities rather than circulating and this can cause blood clots,” Kunutsor explained on the potential mechanisms behind the association between prolonged TV viewing and VTE risk.

“Finally, binge-watchers tend to eat unhealthy snacks which may lead to obesity and high blood pressure which both raise the likelihood of blood clots,” he added.

Nonetheless, as studies included in the meta-analysis were observational in nature, the researchers cautioned against drawing any causation effect from the association. Also, they could not determine if there was a dose–response relationship or the threshold duration of TV viewing associated with VTE risk, as the data available only allowed them to categorize participants viewing time as >4 hours vs <2.5 hours a day.   

“Our results suggest that we should limit the time we spend in front of the television. Long periods of TV watching should be interspersed with movement to keep the circulation going. Generally speaking, if you sit a lot in your daily life – for example your work involves sitting for hours at a computer – be sure to get up and move around from time to time,” concluded Kunutsor.