Cardiovascular risk factors and risk of venous thromboembolism

Abstract

Venous thromboembolism (VTE), including deep vein thrombosis and pulmonary embolism, is a common disease, with serious short- and long-term complications and a potential fatal outcome. Despite the knowledge of several inherited and acquired risk factors for VTE, still 30-50 % of the VTE events occur in the absence of obvious predisposing factors. Traditionally, arterial and venous thrombosis has been considered as separate disease entities with different pathology, epidemiology and treatments. However, recently this concept has been challenged, and a potential link between arterial cardiovascular disease and VTE has been suggested. The aim of this thesis was to investigate the impact of traditional cardiovascular risk factors on the risk of VTE in a prospective population-based study. Subjects were recruited from the fourth survey of the Tromsø study, conducted in 1994-95. A total of 27 158 men and women, aged 25-97 years, participated. Incident VTE events were registered from the date of inclusion through the end of follow-up, September 1, 2007. In summary, age, male gender, obesity, mean platelet volume and family history of myocardial infarction were identified as risk factors for venous thrombosis, which makes these factors, shared risk factors for both arterial and venous thrombosis. Other traditional cardiovascular risk factors such as serum lipid levels, blood pressure, smoking and diabetes were not associated with risk of VTE. Subjects with the metabolic syndrome had higher risk of VTE, but this relationship was essentially dependent on the presence of abdominal obesity. Taken together, these findings imply that traditional atherosclerotic risk factors are not shared by arterial and venous thrombosis, and suggest that common determinants for arterial and venous thrombosis are probably related to mechanisms of thrombus formation.