PB0530 - Sex-Specific Differences in Procoagulant Profiles

Background: It remains unclear why men have a higher intrinsic risk of venous thromboembolism (VTE) than women.

Aims: To assess differences in levels of coagulation markers between men and women with and without VTE.

Methods: Data from participants of the MEGA study (population-based case-control study into causes of VTE) with available blood samples were used, excluding those with active malignancy, under estrogen-based hormone therapy and/or anticoagulant therapy, or pregnant at index or blood sampling. Mean differences and 95% confidence intervals of a wide array of coagulation markers were estimated for men and women, in the entire group and in pre-defined 10-year age groups, with linear regression adjusting for possible confounders.

Results: 1,706 cases (male: n=869) and 2,436 controls (male: n=1,347) were included (Table 1). Mean levels of coagulation factors were mostly similar between men and women (in both cases and controls) (Fig1A). On the other hand, men had a lower normalized activated protein C (APC) sensitivity ratio (Fig1E) and a more pronounced hypofibrinolytic tendency than women (Fig1C) until the age group of 41-50 years, after which women presented levels similar to men (in both cases and controls). With regard to thrombin generation (Fig1D), women (in both cases and controls) had higher endogenous thrombin potential (ETP) and thrombin peak, as well as shorter time to thrombin peak and lag time compared to men. These differences between the sexes became less apparent with age.

Conclusion(s): Our findings show substantial sex-specific differences in coagulation profiles in both patients with VTE and subjects without. Overall, men seemed to have a higher hypofibrinolytic tendency and women a higher thrombin generation potential. Of note, coagulation profiles became more similar between the sexes after the age of 50.