17Β-ESTRADIOL INDUCED EFFECTS ON PERIPHERAL VASCULAR FUNCTION IN PREMENOPAUSAL WOMEN USING DOPPLER ULTRASOUND

I. Khowailed¹, L. Volland², C. Peters-Brinkerhoff³, H. Lee⁴

¹University of Saint Augustine, Physical Therapy, San Marcos, United States, ²National Hemophilia Foundation, New York, United States, ³University of Saint Augustine, San Marcos, United States, ⁴Gachon University, Incheon, Korea (Democratic People's Republic of)

Background: 17β-Estradiol played a substantial role in the regulation of the vasodilatory responses in healthy young women. The fluctuating level of estrogen concentrations across the menstrual cycle may alter the vascular blood flow The observed changes in the endogenous level of estrogen across the menstrual cycle provides a vasoprotection response for the endothelial function. Evidence has shown that estrogen has an impact on the cardiovascular and cerebrovascular physiology and signaling mechanisms (Williams et al. 2020a), but our understanding of the effect of the fluctuating level of estrogen on the vascular circulation and peripheral blood flow in lower extremity remains unclear.

Purpose: The objective of this study was to examine whether menstrual or monophasic oral contraceptive cycle phases affect the peripheral vascular circulation of the lower limb in healthy, active women.

Methods: Thirty-four women were evaluated during the follicular or inactive-pill phase and the ovulatory or active-pill phase of menstrual or oral contraceptive cycle, respectively. Fourteen premenopausal, eumenorrheic non-oral contraceptive users (non-OCP) (28.9 ± 3.5 years age; 165.0 ± 5.8 cm; 66.8 ± 11.2 Kg) and 15 regularly menstruating monophasic oral contraceptive users (OCP users) (26.4 ± 2.67 years of age; 162.3 ± 8.1 cm; 62.0 ± 9.8 kg) completed the study. Doppler recordings of the femoral and popliteal arteries were obtained. Standard Doppler indices (systolic/diastolic ratio, pulsatility index, and resistance index) were calculated throughout the menstrual and oral contraceptive cycles.

Results: Our results showed no significant interaction in the standard Doppler indices of both the popliteal and femoral arteries between the menstrual phase and the group (p > 0.05). There were no significant group effects between non-OCP users and OCP users, as well as no significant phase effects in all standard Doppler index variable users (p > 0.05).

Conclusions: Vascular blood flow remained unchanged between the early follicular and ovulatory phases of the menstrual cycle and the inactive and active-pill phases of the oral contraceptive cycle.

Implications: The present study demonstrated that, in healthy, active women, vascular blow flow in the lower limb microvasculature remained unchanged between the early follicular and ovulatory phases of the menstrual cycle or the inactive-pill and active-pill phases of the oral contraceptive cycle. Further, no significant differences in microvascular function were found between the specific phases of the menstrual and oral contraceptive cycles tested in this study. These data support that it might not be necessary to control menstrual and oral contraceptive cycle phases, particularly within the specific times evaluated in the present study, when assessing vascular blood flow in young, active women.

Funding acknowledgements: National Research Foundation of Korea grant funded by the Korean government (MSIP; Ministry of Science, ICT and Future Planning) NRF-2020R1F1A1075613

Keywords:
17β-Estradiol
Blood flow
Oral contraceptive

Topics:
Pelvic, sexual and reproductive health

Primary health care

Did this work require ethics approval? Yes

Institution: University of Saint Augustine

Committee: Institutional Review Board of the University of Saint Augustine

Ethics number: 0801-018