Menstrual Phase Affects Coagulation and Hematological Parameters during Central Hypovolemia

Abstract

Background: It has been reported that women have a higher number of heart attacks in the “follicular phase” of the menstrual cycle. We, therefore, tested the hypothesis that women in the follicular phase exhibit higher coagulability. As lower body negative pressure (LBNP) has been used previously to assess coagulation changes in whole blood (WB) samples in men and women, effects of menstrual phase on coagulation was assessed during LBNP. Methods: Seven women, all healthy young participants, with no histories of thrombotic disorders and not on medications, were tested in two phases of the menstrual cycle (early follicular (EF) and mid-luteal (ML)). LBNP was commenced at −10 mmHg and increased by −10 mmHg every 5 min until a maximum of −40 mmHg. Recovery up to 10 min was also monitored. Blood samples were collected at baseline, at end of LBNP, and at end of recovery. Hemostatic profiling included comparing the effects of LBNP on coagulation values in both phases of the menstrual cycle using standard coagulation tests, calibrated automated thrombogram, thrombelastometry, impedance aggregometry, and markers of thrombin formation. Results: LBNP led to coagulation activation determined in both plasma and WB samples. During both phases, coagulation was affected during LBNP, as reflected in their decreased partial thromboplastin time (PTT) and elevated coagulation factor VIII FVIII, F1 + 2, and thrombin-antithrombin (TAT) levels. Additionally, during the ML phase, greater PT [%] and shorter time to peak (ttPeak) values (implying faster maximum thrombin formation) suggest that women in the ML phase are relatively hypercoagulable compared to the early follicular phase. Conclusions: These results suggest that thrombosis occurs more during the midluteal phase, a finding with substantial medical implications.

Coagulation hallmark indicators of menorrhagia in a comparative study between menorrhagic and healthy women attending Bungoma County Referral Hospital in Kenya

“…These ndings also contradicted a study conducted in the United States of America (15), which showed that PT levels were comparable between menorrhagic and non-menorrhagic women. The prolonged PT and INR and their association with menorrhagia in the current study could be attributed to the fact that women in the mid-luteal phase are more hypercoagulable than women in the early follicular phase (33). Most of those previous investigations associated prothrombin time with adenomyosis (34) but not directly with menorrhagia.…”

Coagulation Changes during Central Hypovolemia across Seasons

“…An important limitation of this study is that the data shown here are pooled data from males and females and also do not take into account menstrual cycle phases or whether the females were taking oral contraceptives (OCs). While this could be a limitation, as the sex of the participants (Cvirn et al 2019) [3] and the menstrual phases (Goswami et al 2020) [51] are known to affect coagulation, we did not include these aspects in our data analysis, as assessment of differences across the sexes or phases of the menstrual cycle were not the aims of this study. Future studies should examine effects of seasons on coagulation parameters across the sexes of the participants and phases of the menstrual cycle.…”

Developing a “dry lab” activity using lower body negative pressure to teach physiology

“…Indeed, LBNP alone or in combination with head up tilt (HUT) has been used to assess systemic responses as subjects reach the end of their cardiovascular stability and develop a presyncopal state (9). Coagulatory activities have also been studied during LBNP (6,10,11) and at presyncope (12). Studying the impact of LBNP activity in the laboratory setting can also reinforce the need to identify possible confounding variables that can potentially affect cardiovascular and hormonal responses associated with acute Correspondence: N. Goswami (e-mail: nandu.goswami@medunigraz.at).…”