Thromboelastography-Based Evaluation of Gender-Associated Hypercoagulability

Abstract

Background: Age, race, and gender differences in coagulation status of healthy volunteers have been reported in previous case series; however, rigorous multivariate analysis adjusting for these factors is lacking. We aimed to investigate the effects of age, race, and gender on baseline coagulation status in healthy volunteers.

Methods: Thirty healthy volunteer controls with no history of bleeding or thrombotic events and no previous anticoagulant or antiplatelet use were recruited. Citrated and heparinized blood samples were drawn, and kaolin and platelet-mapping thromboelastography (TEG) assays performed.

Results: Thirty participants had a mean age of 37, mean body mass index of 29 kg/m², and were 47% African-American and 70% female. Women were significantly older than men (40 ± 11 y vs 28 ± 7 y, P = .002); there were no significant differences in demographics by race. Multivariate analysis of variance for the effect of age, race, and gender across TEG parameters yielded evidence for gender differences in hypercoagulability (Pillai's trace P = .02), which appear to be driven by differences in K-time, alpha angle, maximal amplitude, and G parameter. Women were hypercoagulable compared to men, as manifested by shorter K-time, steeper alpha angle, higher maximal amplitude, and larger G parameter.

Discussion: Women at baseline have relatively hypercoagulable fibrin deposition kinetics, platelet contributions to clot formation, and overall clot strength compared to men, even when adjusted for age and race. Additional research is needed to specifically detail the key patient-level factors, clinical implications, and opportunities for tailored therapy related to gender-associated hypercoagulability.

Keywords: gender dimorphism; hypercoagulability; thromboelastography.

Figure 1.

TEG parameters in females versus males. Abbreviations: MA, maximal amplitude; AA, arachidonic acid; ADP, adenosine diphosphate.