Effects of menstrual cycle and menopause on internal carotid artery shear-mediated dilation in women

Abstract

This study aimed to elucidate the effects of change in estrogen during the menstrual cycle and menopause on shear-mediated dilation of the internal carotid artery (ICA), a potential index of cerebrovascular endothelial function. Shear-mediated dilation of the ICA and serum estradiol were measured in 11 premenopausal (Pre-M, 21±1yrs), 13 perimenopausal (Peri-M, 49±2yrs), and 10 postmenopausal (Post-M, 65±7yrs) women. Measurements were made twice within the Pre-M group at their early follicular (EF, lower estradiol) and late follicular (LF, higher estradiol) phases. Shear-mediated dilation was induced by 3min of hypercapnia (target PETCO2 +10mmHg from individual baseline) and was calculated as the percent rise in peak diameter relative to baseline diameter. ICA diameter and blood velocity were simultaneously measured by Doppler ultrasound. In Pre-M, shear-mediated dilation was higher during the LF phase than during the EF phase (P<0.01). Comparing all groups, shear-mediated dilation was reduced across the menopausal transition (P<0.01), and Pre-M during the LF phase showed the highest value (8.9±1.4%) compared with other groups (Pre-M in EF, 6.4±1.1%; Peri-M, 5.5±1.3%; Post-M, 5.2±1.9%, P<0.05 for all). Shear-mediated dilation was positively correlated with serum estradiol even after adjustment of age (P<0.01, r=0.55, age-adjusted; P=0.02, r=0.35). Collectively, these data indicate that controlling the menstrual cycle phase is necessary for the cross-sectional assessments of shear-mediated dilation of the ICA in premenopausal women. Moreover, current findings suggest that a decline in cerebrovascular endothelial function may be partly related to the reduced circulating estrogen levels in peri- and postmenopausal women.

Dynamic onset response of the internal carotid artery to hypercapnia is blunted in children compared with adults

“…Last, we do not consider how sex differences may influence ICA hemodynamics in children or adults. There is evidence that ICA dilation increases from the low to the high estradiol phase of the menstrual cycle (Iwamoto et al, 2021 ) and assessment of monthly hormonal changes, although challenging, would be valuable for a more thorough developmental understanding of CBF regulation.…”

Roles of Hormone Replacement Therapy and Menopause on Osteoarthritis and Cardiovascular Disease Outcomes: A Narrative Review

“…Furthermore, this study reported that the carotid artery dilation was improved with higher serum estradiol levels, even after controlling for age. These results point to an intrinsic role of estrogen in the regulation of CVD risk, independent of aging, through the menopause transition ( 69 ). Additionally, investigations into subclinical markers of CVD progression indicative of vascular disturbance also suggest dysfunction emerges across the menopause transition.…”

“…Recent research by Iwamoto and colleagues ( 69 ) examining internal carotid artery shear-mediated dilation as an early predictor of CVD found that dilation was impaired in peri- and post-menopausal women, as compared to pre-menopausal women. Importantly, women included in this trial were not using any type of medication, although there was no exclusion of prior use of HT.…”

Clinical assessments of cerebrovascular health: is there a neED(D) for cerebral shear‐mediated dilatation?

“…The results suggest that declines in cerebrovascular function with ageing may be partially mediated by reduced levels of circulating oestradiol (Iwamoto et al . 2021). Whether the transient CO 2 test is reflective of changes in cerebrovascular NO‐mediated EDD with ageing, exercise and across the menstrual cycle or menopausal transition requires further investigation.…”