Sex-related differences in rapid-onset vasodilation: impact of aging

Abstract

Rapid-onset vasodilation (ROV) in response to a single muscle contraction is attenuated with aging. Moreover, sex-related differences in muscle blood flow and vasodilation during dynamic exercise have been observed in young and older adults. The purpose of the present study was to explore if sex-related differences in ROV exist in young (n=36, 25±1 yr) and older (n=32, 66±1 yr) adults. Subjects performed single forearm contractions at 10%, 20%, and 40% maximal voluntary contraction. Brachial artery blood velocity and diameter were measured with Doppler ultrasound, and forearm vascular conductance (ml·min-1·100 mmHg-1) was calculated from blood flow (ml·min-1) and mean arterial pressure (mmHg) and used as a measure of ROV. Peak ROV was attenuated in women across all relative intensities in the young and older groups (P<0.05). In a subset of subjects with similar absolute workloads (~5 kg and ~11kg), age-related differences in ROV were observed among both women and men (P<0.05). However, only older women demonstrated an attenuated peak ROV compared to men (91±6 vs. 121±11 ml·min-1·100 mmHg-1, P<0.05), a difference not observed in the young group (134±8 vs. 154±11 ml·min-1·100 mmHg-1, P=0.15). Additionally, examining the slope of peak ROV across contraction intensities indicated a blunted response in older women compared to their young counterparts (P<0.05), with no differences observed between older and young men (P=0.38). Our data suggest that sex-related differences in the rapid vasodilatory response to single muscle contractions exist in older but not young adults, such that older women have a blunted response compared to older men.

Vascular Responses to Passive and Active Movement in Premenopausal Females: Comparisons across Sex and Menstrual Cycle Phase

“…This speculation is supported in prior research that highlighted significant improvements in vascular function during the phase of the menstrual cycle where circulating estrogen levels are typically highest (e.g., late follicular [LF] vs early follicular [EF] phase) (2–7). In contrast, current research in PMF using more standardized vascular assessments and menstrual cycle phase methodology have identified similar, or lower (8), vascular function when compared with age-matched men (9,10), as well as no intraindividual differences across menstrual cycle phases (8,11,12). In addition, studies subjecting the vasculature of PMF to insult (altered blood flow patterns, acute hyperglycemia) frequently, but not always (13), report the absence of vascular protection between sexes (14) or across menstrual cycle phases (2,15,16).…”

Customizing Functional Rehabilitation and Return to Sport in the Female Overhead Athlete

“…14 There is some evidence that as women age, their rapid vasodilatory response is decreased compared with men their age and both younger men and women. 15 This could affect their ability to regain strength after an injury/surgical intervention.…”