Prolonged sitting: a new and underestimated risk factor of venous thromboembolism

Venous thromboembolic disease is a multicausal disease that results from an interaction of genetic factors and environmental effects.

Recently, increasing importance has been placed on some of the risk factors in particular: older age, obesity, and immobility. There has

been an increasing number of academic publications on thromboembolic events due to prolonged rigid sitting. To date, case reports or

case series have been published describing often fatal cases resulting from long travel, sitting at work as well as participating in a computer

game marathon. However, only a few studies have been conducted dealing with a more accurate definition of prolonged sitting and

evaluation of the associated risk of thromboembolic event. The most recent study of this type performed so far has defined prolonged

seated immobility as sitting for a period of ≥ 10 hours within 24 hours, at least for 2 hours in succession, during 4 weeks prior to the event,

and has shown a 2.8-fold increase in the risk of thromboembolism following such prolonged sitting. Venous stasis, vein oppression, and

haemoconcentration are likely to play a role in pathophysiology, and the risk substantially increases due to synergic interaction with other



risk factors: Prolonged sitting has been an underappreciated (yet modifiable) risk factor of thromboembolism. Therefore, education of both

experts and the public as well as implementation of appropriate preventive measures in some professions are required.

Keywords: deep venous thrombosis, pulmonary embolism, risk factor