1. Variation in arterial compliance and endothelial function during the menstrual cycle Meeme A1*, Namugowa A2, Tichiwanuyi T2, Siyonela2 Department of Obstetrics and Gynaecology, School of Medicine, Faculty of Health Sciences, WSU Department of Physiology, School of Medicine, Faculty of Health Sciences, WSU
Introduction
Results
Results Cont’d
±Std. Dev.
±St. Err.
Mean
Pulse wave velocity
m/s
4.0
4.4
4.8
5.2
5.6
6.0
6.4 EF LF EL
Variable
Early follicular
Late follicular
Early luteal
p-value (95 CI)
Central SP (mmHg)
97.5 ± 9.2
98.0 ± 4.5
98.8 ± 6.6
>0.05
Central DP (mmHg)
73.7 ± 7.6
73.5 ± .6
73.1 ± 5.1
Augmentation index (75) (%)
1.6 ± 3
6.3 ± 3
4.1 ± 4
Pulse wave velocity(m/s)
5.1 ± 0.3
4.8 ± 0.1
Reactive hyperemia index
1.66 ± 0.09
1.62 ± 0.16
1.47 ± 0.11
> 0.05
Female sex hormones have been implicated in cardioprotection of premenopausal women. However the effect of their natural fluctuation on cardiovascular action is still controversial.
Aim
The purpose of this study was to study the changes in vascular function during the menstrual cycle phases
Figure 2. Graph showing pulse wave velocity in the 3 phases of the cycle
±Std. Dev.
±Std. Err.
Mean
Reactive hyperemia index
1.0
1.2
1.4
1.6
1.8
2.0
2.2 EF LF EL
Methods
Table showing blood pressure, vascular compliance and endothelial function in the different phases of the menstrual cycle
Figure 3. Graph showing reactive hyperemia index in the 3 phases of the cycle
Discussion
Graphs
EndoPAT (Itamar,Israel)
No significant difference was observed in the vascular function across the menstrual cycle. This could be due to;
The small sample size
ii) inability to measure the female hormones at the different phases of the cycle
Recommendation
A new study be done with a bigger sample size as well as measure hormonal levels during the cycle
Augmentation index at 75bpm
±Std. Dev.
±Std. Err.
Mean %
-10 -6 -2 2 6 10 14 18 EF LF EL
SphygmoCor (AtCor Medical)
Participants
References
10 healthy women aged 21.3±1.3 with regular menses recruited from WSU
Arterial compliance (Pulse wave velocity (PWV and Augmentation index Alx) was measured using the SphygmoCor (AtCor Australia).
Reactive hyperemia index (RHI; index of endothelial function) was measured using the EndoPAT (Itamar-medical, Caesarea, Israel)
Studies were done during the early follicular (EF; day 2), late follicular (LF; day 12) and early luteal (EL; day 16) phases of the cycle.
Hashimoto et al, Modulation of endothelium-dependent flow mediated dilatation of the brachial artery by sex and menstrual cycle. Circulation: 92:
Williams et al Variations in endothelial function and arterial compliance during the menstrual cycle. J. Clin Endoc met 86:
Lieberman et al, estrogen improves endothelial dependent flow mediated vasodilatation in postmenopausal women. Ann Inter Med 121:
Figure 1. Graph showing augmentation index at 75bpm in the 3 phases of the cycle
Acknowledgement
WSU Research development for financial assistance