The effect of BMI on haemostasis: Implications for thrombosis in women's health.

Obesity has reached epidemic proportions and is a well-recognised risk factor for venous thromboembolism (VTE). This article summarises the current understanding of obesity and debates how obesity induces this increased risk of VTE. Obesity is associated with prothrombotic changes which have been well-characterised and include increased levels of plasminogen activator-1, von Willebrand factor, fibrinogen and evidence of increased coagulation and platelet activation; however, these changes do not seem to account for all the increased risk. Accumulating evidence suggests a significant role for increased tissue factor expression and signalling in this relationship, with increased tissue factor expression present in adipose and possibly systemic tissues, induced by adipose generated cytokines. Lastly, there is a strong suggestion that decreased venous flow due to venous enlargement may play the major role in increased VTE risk with obesity.