ORLANDO, FLA. — Declining estrogen levels during late perimenopause and postmenopause substantially affect the peripheral vasculature, recent study data suggest.
Specifically, lower estrogen levels during these periods were associated with larger common carotid artery (CCA) adventitial diameter, Rachel P. Wildman, Ph.D., reported at an international conference on women, heart disease, and stroke.
This can be problematic, because greater baseline dilation limits the future ability to dilate and compensate for adverse conditions such as increased blood pressure, explained Dr. Wildman of Tulane University, New Orleans.
In 377 white and African American women from the Pittsburgh and Chicago sites of the Study of Women's Health Across the Nation (SWAN), an ongoing multiethnic, multisite longitudinal study of the menopausal transition, the cross-sectional relationship between the CCA adventitial diameter and both menopausal status and sex hormones was assessed.
Artery diameter was measured using B-mode ultrasound, and sex-hormone tests evaluated levels of estrogen, testosterone, FSH, sex hormone binding globulin, the free androgen index, testosterone not bound by sex hormone binding globulin, and androgen excess.
The women had a mean age of 50 years, and 149 were in late perimenopause or postmenopause. These women, compared with those in pre- or early perimenopause, had significantly higher total and LDL cholesterol, lower HDL cholesterol, lower estrogen, and higher androgen excess levels.
CCA adventitial diameter in the late perimenopausal and postmenopausal women were significantly larger overall, compared with those in pre- or early perimenopause (6.84 mm vs. 6.70 mm), but the differences appeared to be limited to those with higher baseline cholesterol levels.
As for the relationship between sex hormones and CCA adventitial diameter, only decreased estrogen levels were significantly associated with increased diameters, but in the subset of patients with systolic blood pressure over 140 mm Hg, decreased androgen levels were also strongly associated with larger diameter.
The findings suggest that the menopausal transition with its accompanying decrease in estrogen levels is associated with decreased vascular tone, and it appears that women with higher cholesterol and blood pressure are at the greatest risk, she said,
Follow-up data in the SWAN participants are being collected by the investigators for further evaluation of these interactions.