Menstrual Phase Affects Coagulation and Hematological Parameters during Central Hypovolemia

Area of Science:

• Reproductive endocrinology and hemostasis research.
• Cardiovascular health in women's reproductive cycles.

Background:

• Previous reports indicate a higher incidence of heart attacks in women during the follicular phase.
• The study investigates the hypothesis that women exhibit increased blood coagulability during the follicular phase.
• Lower body negative pressure (LBNP) is utilized to assess coagulation changes.

Purpose of the Study:

• To test the hypothesis of increased coagulability in the follicular phase.
• To assess the effects of menstrual phase on blood coagulation during LBNP.
• To compare coagulation profiles between the early follicular and mid-luteal phases.

Main Methods:

• Seven healthy women were studied in their early follicular (EF) and mid-luteal (ML) phases.
• Lower body negative pressure (LBNP) was applied incrementally up to -40 mmHg.
• Hemostatic profiling included standard coagulation tests, thrombelastometry, and markers of thrombin formation.

Main Results:

• LBNP induced coagulation activation in both plasma and whole blood (WB) samples.
• Coagulation was altered in both phases, with decreased partial thromboplastin time (PTT) and elevated markers like FVIII and thrombin-antithrombin (TAT).
• The mid-luteal phase showed greater prothrombin time (PT) and shorter time to peak (ttPeak), indicating hypercoagulability compared to the early follicular phase.

Conclusions:

• The mid-luteal phase is associated with a hypercoagulable state in women.
• These findings suggest a higher propensity for thrombosis during the mid-luteal phase.
• The results have significant implications for understanding cardiovascular risk in women.