Shane J McGinty, Evan L Matthews, Jody L Greaney, J Kevin Shoemaker, Megan M Wenner
{"title":"Sympathetic baroreflex sensitivity is enhanced in postmenopausal women.","authors":"Shane J McGinty, Evan L Matthews, Jody L Greaney, J Kevin Shoemaker, Megan M Wenner","doi":"10.1152/japplphysiol.00833.2023","DOIUrl":null,"url":null,"abstract":"<p><p>The sympathetic nervous system is critical for regulating blood pressure (BP) via the arterial baroreflex and sympathetic transduction in the peripheral vasculature. These mechanisms interact, and both may be altered with aging and impacted by menopause. Although age-related decreases in sympathetic transduction have been demonstrated in women, it remains unclear whether sympathetic baroreflex sensitivity (BRS) is impaired in postmenopausal women (POST). We tested the hypothesis that sympathetic BRS would be enhanced in POST compared with premenopausal women (PRE). We examined beat-by-beat BP and muscle sympathetic nerve activity (MSNA) in 19 PRE (22 ± 2 yr, 22 ± 3 kg/m<sup>2</sup>) and 12 POST (57 ± 5 yr, 24 ± 2 kg/m<sup>2</sup>) during 10 min of rest. Spontaneous sympathetic BRS was quantified as the slope of a linear regression between MSNA burst incidence and diastolic BP. Sympathetic transduction to mean arterial pressure (MAP) for the 10 cardiac cycles following spontaneous MSNA bursts was assessed via signal averaging method. Resting MAP was similar (PRE: 82 ± 8 vs. POST: 85 ± 8 mmHg, <i>P</i> = 0.43), whereas resting MSNA was elevated in POST (PRE: 10 ± 6 vs. POST: 45 ± 16 bursts/100 heart beats, <i>P</i> < 0.0001). Spontaneous sympathetic BRS was enhanced in POST (PRE: -2.0 ± 1.2 vs. POST: -5.2 ± 1.9 bursts/beat/mmHg, <i>P</i> < 0.0005). Sympathetic transduction to MAP was attenuated in POST (time: <i>P</i> < 0.001, group: <i>P</i> < 0.001, interaction: <i>P</i> < 0.01). These data suggest that sympathetic BRS may be enhanced in POST. Consistent with recent hypotheses, enhanced sensitivity of the arterial baroreflex's neural arc may signify a compensatory response to reduced efficiency of the peripheral arterial baroreflex arc (i.e., sympathetic transduction) to preserve BP buffering capacity.<b>NEW & NOTEWORTHY</b> Studies examining sympathetic baroreflex function with aging remain equivocal, with some studies showing an increase, decrease, or no change in sympathetic baroreflex sensitivity (BRS) in older adults compared with younger adults. With aging, women experience unique physiological changes due to menopause that influence autonomic function. For the first time, we show that postmenopausal women exhibit a greater sympathetic BRS compared with young premenopausal women.</p>","PeriodicalId":15160,"journal":{"name":"Journal of applied physiology","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of applied physiology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1152/japplphysiol.00833.2023","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/7/4 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"PHYSIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The sympathetic nervous system is critical for regulating blood pressure (BP) via the arterial baroreflex and sympathetic transduction in the peripheral vasculature. These mechanisms interact, and both may be altered with aging and impacted by menopause. Although age-related decreases in sympathetic transduction have been demonstrated in women, it remains unclear whether sympathetic baroreflex sensitivity (BRS) is impaired in postmenopausal women (POST). We tested the hypothesis that sympathetic BRS would be enhanced in POST compared with premenopausal women (PRE). We examined beat-by-beat BP and muscle sympathetic nerve activity (MSNA) in 19 PRE (22 ± 2 yr, 22 ± 3 kg/m2) and 12 POST (57 ± 5 yr, 24 ± 2 kg/m2) during 10 min of rest. Spontaneous sympathetic BRS was quantified as the slope of a linear regression between MSNA burst incidence and diastolic BP. Sympathetic transduction to mean arterial pressure (MAP) for the 10 cardiac cycles following spontaneous MSNA bursts was assessed via signal averaging method. Resting MAP was similar (PRE: 82 ± 8 vs. POST: 85 ± 8 mmHg, P = 0.43), whereas resting MSNA was elevated in POST (PRE: 10 ± 6 vs. POST: 45 ± 16 bursts/100 heart beats, P < 0.0001). Spontaneous sympathetic BRS was enhanced in POST (PRE: -2.0 ± 1.2 vs. POST: -5.2 ± 1.9 bursts/beat/mmHg, P < 0.0005). Sympathetic transduction to MAP was attenuated in POST (time: P < 0.001, group: P < 0.001, interaction: P < 0.01). These data suggest that sympathetic BRS may be enhanced in POST. Consistent with recent hypotheses, enhanced sensitivity of the arterial baroreflex's neural arc may signify a compensatory response to reduced efficiency of the peripheral arterial baroreflex arc (i.e., sympathetic transduction) to preserve BP buffering capacity.NEW & NOTEWORTHY Studies examining sympathetic baroreflex function with aging remain equivocal, with some studies showing an increase, decrease, or no change in sympathetic baroreflex sensitivity (BRS) in older adults compared with younger adults. With aging, women experience unique physiological changes due to menopause that influence autonomic function. For the first time, we show that postmenopausal women exhibit a greater sympathetic BRS compared with young premenopausal women.
期刊介绍:
The Journal of Applied Physiology publishes the highest quality original research and reviews that examine novel adaptive and integrative physiological mechanisms in humans and animals that advance the field. The journal encourages the submission of manuscripts that examine the acute and adaptive responses of various organs, tissues, cells and/or molecular pathways to environmental, physiological and/or pathophysiological stressors. As an applied physiology journal, topics of interest are not limited to a particular organ system. The journal, therefore, considers a wide array of integrative and translational research topics examining the mechanisms involved in disease processes and mitigation strategies, as well as the promotion of health and well-being throughout the lifespan. Priority is given to manuscripts that provide mechanistic insight deemed to exert an impact on the field.