Changes in peripheral but not central pulse wave velocity with estradiol administration is positively correlated with muscle sympathetic nerve activity

Abstract

To investigate how estrogen affects autonomic and cardiovascular function, we measured muscle sympathetic nerve activity (MSNA), and central and peripheral pulse wave velocities (PWV) in 8 young healthy women after 3 days of endogenous sex hormone suppression (via gonadotropin‐releasing hormone antagonism). Five subjects continued hormone suppression for 2 days, combined with 0.2mg/day transdermal estradiol, and were retested. Estradiol administration decreased peripheral PWV (p<0.05), a finding that does not exist during normal menstrual fluctuations. There was no change in central PWV (p=0.27). In addition, we used linear regression analyses to explore the relationship between MSNA and PWV. Across all subjects and conditions, peripheral (brachial‐ankle) PWV was positively correlated with MSNA bursts/min (R2=0.33, p=0.05) and bursts/100 heartbeats (R2=0.39, p=0.03), whereas no relationships existed between central (carotid‐femoral) PWV and MSNA parameters (bursts/min, R2<0.01, p=0.90; and bursts/100 heartbeats, R2<0.01, p=0.77). These data suggest sympathetic outflow to the peripheral arteries may explain the changes in peripheral PWV with estrogen administration. Degree of sympathetic innervation in the specific arteries studied may explain the differences between peripheral and central PWV measurements.Supported by NIH Grant HL081671.