Low‐Flow‐Mediated Constriction is Reduced in Healthy Postmenopausal Women

Abstract

Vascular function declines in women after menopause, and has been characterized by a reduction in brachial artery flow‐mediated dilation (FMD). Low‐flow‐mediated constriction (L‐FMC) is an assessment of resting arterial tone that serves as a complementary measure of vascular function. Although L‐FMC has been shown to be reduced in certain diseased populations such as coronary artery disease, to our knowledge it is unknown if L‐FMC is altered with age/menopause. Accordingly, the purpose of this study was to test the hypothesis that postmenopausal women (PMW) have reduced L‐FMC values compared to young women (YW). We assessed vascular function in 16 PMW (59±1 years, 24±1 kg/m2) and 19 YW (21±1 years, 23±1 kg/m2). Longitudinal images of the brachial artery were acquired using ultrasound (GE Logic P5). A blood pressure cuff was placed just distal to the olecranon process and inflated to 200mmHg for five minutes. Images were recorded continuously during baseline (1‐minute), cuff occlusion (5‐ minutes), and cuff release (2‐minutes). L‐FMC was calculated as a percent change from baseline diameter to the average diameter during the last 30 seconds of cuff occlusion. FMD was calculated as a percent change from baseline diameter to peak diameter following cuff release. Total vessel reactivity was calculated as the sum of the absolute value of L‐FMC and FMD. All women were normotensive, although PMW had higher resting mean arterial pressure (PMW: 90±2 mmHg, YW: 82±2 mmHg; P<0.01). L‐FMC was reduced in PMW compared to YW (PMW: −1.67±0.36% vs YW: −2.84±0.35%; P=0.03). FMD was lower in PMW compared to YW (PMW: 5.47±0.54% vs YW: 7.33±0.53%; P=0.02). Total vessel reactivity was also lower in PMW (PMW: 7.32±0.67% vs YW: 10.17±0.57%; P<0.01). Consistent with previous findings, PMW have lower FMD values compared to YW. In addition, PMW also have reduced L‐FMC compared to YW. These findings suggest that L‐FMC may be a useful measure of vascular function with healthy aging.Support or Funding InformationSupported by: NIH Grant P20 GM 103446, U54 GM 104941, P20 GM113125, and University of Delaware Research Foundation.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.