Venous thrombosis is a disease that occurs in 1-2 per 1000 people per year. At the time of their first venous thrombosis, approximately 50% of women are exposed to reproductive risk factors (oral... Show moreVenous thrombosis is a disease that occurs in 1-2 per 1000 people per year. At the time of their first venous thrombosis, approximately 50% of women are exposed to reproductive risk factors (oral contraception, postmenopausal hormone therapy, pregnancy and the puerperium). In this thesis, we showed that these women are at particularly high risk of venous thrombosis if they have previously experienced an episode of superficial vein thrombosis, or are over the age of 50 years (Chapters 2 and 3). There is no known male counterpart to female reproductive risk factors. Nevertheless, the incidence of venous thrombosis is approximately similar in men and women. In this thesis we established that, once female reproductive risk factors are taken into account, men have an approximately twofold higher risk of both first and recurrent venous thrombosis than women (Chapters 4 and 5). Further to these findings, in Chapter 6, we reviewed the literature on sex-specific risk factors for venous thrombosis. We hypothesized that sex-specific genetic risk factors, an excess in overweight and smoking, or hypercoagulable changes such as microalbuminuria may explain the higher risk of venous thrombosis in men than in women. Show less
