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Título:
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Global Reach 2018: reduced flow-mediated dilation stimulated by sustained increases in shear stress in high-altitude excessive erythrocytosis.
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Autores:
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Tremblay, Joshua C. ;
Coombs, Geoff B. ;
Howe, Connor A. ;
Vizcardo-Galindo, Gustavo A. ;
Figueroa-Mujica, Romulo J. ;
Bermudez, Daniela ;
Tymko, Michael M. ;
Villafuerte, Francisco C. ;
Ainslie, Philip N. ;
Pyke, Kyra E.
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Tipo de documento:
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texto impreso
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Editorial:
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American Physiological Society, 2019-12-06T21:04:46Z
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Nota general:
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info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es
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Idiomas:
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Inglés
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Palabras clave:
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Editados por otras instituciones
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Artículos
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Artículos en revistas indizadas
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Resumen:
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Excessive erythrocytosis [EE; hemoglobin concentration (Hb) >/= 21 g/dL in adult men] is a maladaptive high-altitude pathology associated with increased cardiovascular risk and reduced reactive hyperemia flow-mediated dilation (FMD); however, whether a similar impairment occurs in response to more commonly encountered sustained increases in shear stress [sustained stimulus (SS)-FMD] over a range of overlapping stimuli is unknown. We characterized SS-FMD in response to handgrip exercise in Andeans with and without EE in Cerro de Pasco, Peru (4,330 m). Andean highlanders with EE (n = 17, Hb = 23.2 +/- 1.2 g/dL) and without EE (n = 23, Hb = 18.7 +/- 1.9 g/dL) performed 3 min of rhythmic handgrip exercise at 20, 35, and 50% of maximum voluntary contraction (MVC). Duplex ultrasound was used to continuously record blood velocity and diameter in the brachial artery, and blood viscosity was measured to accurately calculate shear stress. Although baseline shear stress did not differ, Andeans with EE had 22% lower shear stress than Andeans without at 50% MVC (P = 0.004). At 35 and 50% MVC, SS-FMD was 2.1 +/- 2.0 and 2.8 +/- 2.7% in Andeans with EE compared with 4.1 +/- 3.4 and 7.5 +/- 4.5% in those without (P = 0.048 and P /= 21 g/dL) is a maladaptation to chronic hypoxia exposure and is associated with increased cardiovascular risk. We examined flow-mediated dilation (FMD) in response to sustained elevations in shear stress achieved using progressive handgrip exercise [sustained stimulus (SS)-FMD] in Andean highlanders with and without EE at 4,330 m. Andeans with EE demonstrated lower SS-FMD compared with those without. Heightened hemoglobin concentration was related to lower SS-FMD in Andeans with EE.
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En línea:
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http://repositorio.upch.edu.pe/handle/upch/7608
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