Health

Sitting all day increases risk of blood clots in the lungs

Pulmonary embolism common cause of heart disease

© Ana Blazic - Fotolia.com

Women who spend a good part of their day sitting are two to three times more likely to develop a life-threatening blood clot in their lungs than more active women, according to a new study.

The study is the first to prove that a sedentary lifestyle increases your risk of developing a pulmonary embolism, a common cause of heart disease.

Although the risk is small - equivalent to seven extra cases per 10,000 person years - the findings could have major health ramifications.

Pulmonary embolism develops when a blood clot travels through the bloodstream from the deep veins in the leg and up into the lungs. Symptoms include difficulty breathing, chest pain and coughing.

The researchers followed 69,950 nurses over an 18-year period and found that women who spent more than 41 hours a week sitting outside work had a more than two times higher risk than those who spent less than 10 hours a week sitting outside work.

This remained true even when factors such as age, body mass index and smoking were taken into account.

The study also showed that physical inactivity correlated with heart disease and hypertension and could be one of the hidden mechanisms that link arterial disease and venous disease.

The study "reinforces the notion that prolonged inactivity increases the risk of venous thromboembolism, and it shows how this occurs in everyday life," the researchers wrote.

The authors suggested that public health campaigns aimed at discouraging physical inactivity could reduce the incidence of pulmonary embolism.

The study is published today on bmj.com.