Central, peripheral and resistance arterial reactivity: fluctuates during the phases of the menstrual cycle

Abstract

The purpose of this study was to document the temporal changes in vascular reactivity occurring simultaneously in central, peripheral and microvascular resistance arteries in the same cohort of women during the normal menstrual cycle. Twenty-three (n = 23) women (mean age (+/-SD) = 19 +/- 1 y) were tested during four phases of a normal menstrual cycle. Delineation of the four phases occurred as follows: (1) the early follicular phase; (2) the late follicular (LF) phase; (3) the early luteal (EL) phase; and (4) the late luteal phase. Non-invasive measurement of central hemodynamics and peripheral artery pulse wave velocity (PWV) were performed using applanation tonometry. Measurement of peripheral endothelial function was determined by flow-mediated dilation (FMD) testing in the brachial artery and venous occlusion plethysmography in the forearm and calf resistance arteries. Additionally, plasma NOx and 17beta-estradiol (E) concentrations were measured. Both central (aortic) and peripheral blood pressure (BP) were lowest (P < 0.05) during the LF phase and BP reduction was sustained (P < 0.05) into the EL phase. The timing and amplitude of the reflected pressure wave were attenuated only during the LF phase (P < 0.05). No temporal changes were observed in either central (carotid-femoral) or peripheral PWV (femoral-dorsalis pedis, carotid-radial). Peak forearm and calf blood flow during reactive hyperemia were greatest in LF. Brachial FMD was greatest during the LF phase (P < 0.05). Plasma E and NOx concentrations were highest during the LF phase (P < 0.05). Young premenopausal women experienced an overwhelming pattern of reduced BP and increased systemic vascular reactivity during the LF phase prior to ovulation.

Figure 1

(Top panel) Temporal pattern of brachial and aortic systolic blood pressure during the early follicular (EF), late follicular (LF), early luteal (EL) and late luteal (LL) phases of the menstrual cycles. (Bottom panel) Temporal pattern of brachial and aortic diastolic blood pressure during the EF, LF, EL and LL phases of the menstrual cycle. *P < 0.05 versus EF, EL and LL; †P < 0.05 versus EF and LL; #P < 0.05 versus EF. SBP, systolic blood pressure; DBP, diastolic blood pressure

Figure 2

Temporal pattern of the percent change in round trip travel time of the aortic pressure wave (ΔTp; ms), wasted left ventricular energy (LVEw; dyne/cm²/s) and aortic augmentation index normalized for a heart rate of 75 bpm (Aix at 75; %) during the early follicular (EF), late follicular (LF), early luteal (EL) and late luteal (LL) phases of the menstrual cycle. *P < 0.05 versus EF, EL and LL; †P < 0.05 versus EF and LL; #P < 0.05 versus EF

Figure 3

Temporal pattern of absolute dilation (mm) (top panel), percent dilation (%) (middle panel) and dilation normalized during the first 10 s following cuff release (bottom panel) during flow-mediated dilation (FMD) testing in the brachial artery during the early follicular (EF), late follicular (LF), early luteal (EL) and late luteal (LL) phases of the menstrual cycle. *P < 0.05 versus EF, EL and LL

Figure 4

Temporal pattern of plasma concentrations of nitrite/nitrate (NOx) (top panel) and 17β-estradial (bottom panel) during the early follicular (EF), late follicular (LF), early luteal (EL) and late luteal (LL) phases of the menstrual cycle. *P < 0.05 versus EF, EL and LL