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Cerebrovascular Reactivity and Central Arterial Stiffness in Habitually Exercising Healthy Adults

Reduced cerebrovascular reactivity to a vasoactive stimulus is associated with age-related diseases such as stroke and cognitive decline. Habitual exercise is protective against cognitive decline and is associated with reduced stiffness of the large central arteries that perfuse the brain. In this c...

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Autores principales: Miller, Kathleen B., Howery, Anna J., Harvey, Ronée E., Eldridge, Marlowe W., Barnes, Jill N.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6107836/
https://www.ncbi.nlm.nih.gov/pubmed/30174609
http://dx.doi.org/10.3389/fphys.2018.01096
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author Miller, Kathleen B.
Howery, Anna J.
Harvey, Ronée E.
Eldridge, Marlowe W.
Barnes, Jill N.
author_facet Miller, Kathleen B.
Howery, Anna J.
Harvey, Ronée E.
Eldridge, Marlowe W.
Barnes, Jill N.
author_sort Miller, Kathleen B.
collection PubMed
description Reduced cerebrovascular reactivity to a vasoactive stimulus is associated with age-related diseases such as stroke and cognitive decline. Habitual exercise is protective against cognitive decline and is associated with reduced stiffness of the large central arteries that perfuse the brain. In this context, we evaluated the age-related differences in cerebrovascular reactivity in healthy adults who habitually exercise. In addition, we sought to determine the association between central arterial stiffness and cerebrovascular reactivity. We recruited 22 young (YA: age = 27 ± 5 years, range 18–35 years) and 21 older (OA: age = 60 ± 4 years, range 56–68 years) habitual exercisers who partake in at least 150 min of structured aerobic exercise each week. Middle cerebral artery velocity (MCAv) was recorded using transcranial Doppler ultrasound. In order to assess cerebrovascular reactivity, MCAv, end-tidal carbon dioxide (ETCO(2)), and mean arterial pressure (MAP) were continuously recorded at rest and during stepwise elevations of 2, 4, and 6% inhaled CO(2). Cerebrovascular conductance index (CVCi) was calculated as MCAv/MAP. Central arterial stiffness was assessed using carotid–femoral pulse wave velocity (PWV). Older adults had higher PWV (YA: 6.2 ± 1.2 m/s; OA: 7.5 ± 1.3 m/s; p < 0.05) compared with young adults. MCAv and CVCi reactivity to hypercapnia were not different between young and older adults (MCAv reactivity, YA: 2.0 ± 0.2 cm/s/mmHg; OA: 2.0 ± 0.2 cm/s/mmHg; p = 0.77, CVCi reactivity, YA: 0.018 ± 0.002 cm/s/mmHg(2); OA: 0.015 ± 0.001 cm/s/mmHg(2); p = 0.27); however, older adults demonstrated higher MAP reactivity to hypercapnia (YA: 0.4 ± 0.1 mmHg/mmHg; OA: 0.7 ± 0.1 mmHg/mmHg; p < 0.05). There were no associations between PWV and cerebrovascular reactivity (range: r = 0.00–0.39; p = 0.07–0.99). Our results demonstrate that cerebrovascular reactivity was not different between young and older adults who habitually exercise; however, MAP reactivity was augmented in older adults. This suggests an age-associated difference in the reliance on MAP to increase cerebral blood flow during hypercapnia.
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spelling pubmed-61078362018-08-31 Cerebrovascular Reactivity and Central Arterial Stiffness in Habitually Exercising Healthy Adults Miller, Kathleen B. Howery, Anna J. Harvey, Ronée E. Eldridge, Marlowe W. Barnes, Jill N. Front Physiol Physiology Reduced cerebrovascular reactivity to a vasoactive stimulus is associated with age-related diseases such as stroke and cognitive decline. Habitual exercise is protective against cognitive decline and is associated with reduced stiffness of the large central arteries that perfuse the brain. In this context, we evaluated the age-related differences in cerebrovascular reactivity in healthy adults who habitually exercise. In addition, we sought to determine the association between central arterial stiffness and cerebrovascular reactivity. We recruited 22 young (YA: age = 27 ± 5 years, range 18–35 years) and 21 older (OA: age = 60 ± 4 years, range 56–68 years) habitual exercisers who partake in at least 150 min of structured aerobic exercise each week. Middle cerebral artery velocity (MCAv) was recorded using transcranial Doppler ultrasound. In order to assess cerebrovascular reactivity, MCAv, end-tidal carbon dioxide (ETCO(2)), and mean arterial pressure (MAP) were continuously recorded at rest and during stepwise elevations of 2, 4, and 6% inhaled CO(2). Cerebrovascular conductance index (CVCi) was calculated as MCAv/MAP. Central arterial stiffness was assessed using carotid–femoral pulse wave velocity (PWV). Older adults had higher PWV (YA: 6.2 ± 1.2 m/s; OA: 7.5 ± 1.3 m/s; p < 0.05) compared with young adults. MCAv and CVCi reactivity to hypercapnia were not different between young and older adults (MCAv reactivity, YA: 2.0 ± 0.2 cm/s/mmHg; OA: 2.0 ± 0.2 cm/s/mmHg; p = 0.77, CVCi reactivity, YA: 0.018 ± 0.002 cm/s/mmHg(2); OA: 0.015 ± 0.001 cm/s/mmHg(2); p = 0.27); however, older adults demonstrated higher MAP reactivity to hypercapnia (YA: 0.4 ± 0.1 mmHg/mmHg; OA: 0.7 ± 0.1 mmHg/mmHg; p < 0.05). There were no associations between PWV and cerebrovascular reactivity (range: r = 0.00–0.39; p = 0.07–0.99). Our results demonstrate that cerebrovascular reactivity was not different between young and older adults who habitually exercise; however, MAP reactivity was augmented in older adults. This suggests an age-associated difference in the reliance on MAP to increase cerebral blood flow during hypercapnia. Frontiers Media S.A. 2018-08-17 /pmc/articles/PMC6107836/ /pubmed/30174609 http://dx.doi.org/10.3389/fphys.2018.01096 Text en Copyright © 2018 Miller, Howery, Harvey, Eldridge and Barnes. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Physiology
Miller, Kathleen B.
Howery, Anna J.
Harvey, Ronée E.
Eldridge, Marlowe W.
Barnes, Jill N.
Cerebrovascular Reactivity and Central Arterial Stiffness in Habitually Exercising Healthy Adults
title Cerebrovascular Reactivity and Central Arterial Stiffness in Habitually Exercising Healthy Adults
title_full Cerebrovascular Reactivity and Central Arterial Stiffness in Habitually Exercising Healthy Adults
title_fullStr Cerebrovascular Reactivity and Central Arterial Stiffness in Habitually Exercising Healthy Adults
title_full_unstemmed Cerebrovascular Reactivity and Central Arterial Stiffness in Habitually Exercising Healthy Adults
title_short Cerebrovascular Reactivity and Central Arterial Stiffness in Habitually Exercising Healthy Adults
title_sort cerebrovascular reactivity and central arterial stiffness in habitually exercising healthy adults
topic Physiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6107836/
https://www.ncbi.nlm.nih.gov/pubmed/30174609
http://dx.doi.org/10.3389/fphys.2018.01096
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