A serious and sometimes fatal lung-related vascular disease, pulmonary embolism is caused by obstruction of the pulmonary arteries by blood clots, generally formed in the leg vessels. Toru Shirakawa, from Osaka University (Japan), and colleagues completed an 18-year long study involving 86,024 men and women, ages 40 to 79 years, who self-reported their daily television watching times and who were followed up for a median of 18.4 years. Deaths from pulmonary embolism was identified from death certificates. Length of television watching was divided into three groups: less than 2.5 hours, 2.5 to 4.9 hours and 5 or more hours per day. Risk of death from pulmonary embolism according to length of television watching was calculated after adjusting for age at baseline, gender, history of hypertension, history of diabetes, smoking status, drinking status, body mass index, walking and sports habits and menopausal status. During the follow up period there were 59 deaths from pulmonary embolism. The researchers found that people whose average television viewing time was more than five hours per day had twice the risk of fatal pulmonary embolism as those who watched an average of less than two and a half hours daily. The association was more prominent in people under 60 years of age in whom watching television more than five hours per day was associated with a six-fold risk of fatal pulmonary embolism compared to watching less than two and a half hours. In this age group, watching 2.5 to 4.9 hours tripled risk compared to less than 2.5 hours. The lead investigator comments that: “”We showed that prolonged television viewing may be a risky behaviour for death from pulmonary embolism. Leg immobility during television viewing may in part explain the finding.”
