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Erschienen in: European Journal of Applied Physiology 5/2019

08.03.2019 | Original Article

The effects of aging on the distribution of cerebral blood flow with postural changes and mild hyperthermia

verfasst von: Akemi Ota, Ryosuke Takeda, Daiki Imai, Nooshin Naghavi, Eriko Kawai, Kosuke Saho, Emiko Morita, Yuta Suzuki, Hisayo Yokoyama, Toshiaki Miyagawa, Kazunobu Okazaki

Erschienen in: European Journal of Applied Physiology | Ausgabe 5/2019

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Abstract

Purpose

Cerebral blood flow (CBF) would be impaired with dual stresses of heat and orthostatic changes, even if those stresses are mild, in the elderly with declined cardio- and cerebrovascular functions with aging. To test the hypothesis, we compared the response of blood flow in the internal carotid artery (ICA) and vertebral artery (VA) to dual stresses of heat and orthostatic changes between the elderly and young individuals.

Methods

Nine elderly and eight young healthy men (71.3 ± 3.0 and 23.3 ± 3.1 years, mean ± SD, respectively) underwent measurements of blood flow in the ICA, VA and external carotid artery (ECA) via ultrasonography. The measurements were obtained in sitting and supine positions under normothermic (NT) and mildly hyperthermic (HT) conditions (ambient temperature 28 °C). Esophageal temperatures increased from NT (36.4 ± 0.2 °C, mean ± SE) to HT (37.4 ± 0.2 °C) with lower legs immersion in 42 °C water.

Results

With heat stress, ECA blood flow increased in both postures in both age groups (effect of heat, p < 0.001), whereas ICA blood flow remained unchanged. With postural changes from supine to sitting, ECA blood flow remained unchanged whereas ICA blood flow decreased (effect of posture, p = 0.027) by 18% in NT in the young and by 20% in HT in the elderly. VA blood flow remained unchanged under both heat stress and postural changes.

Conclusions

The CBF is impaired under dual stresses of heat and orthostatic changes in healthy aged individuals, even if the levels of the stresses are mild.
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Metadaten
Titel
The effects of aging on the distribution of cerebral blood flow with postural changes and mild hyperthermia
verfasst von
Akemi Ota
Ryosuke Takeda
Daiki Imai
Nooshin Naghavi
Eriko Kawai
Kosuke Saho
Emiko Morita
Yuta Suzuki
Hisayo Yokoyama
Toshiaki Miyagawa
Kazunobu Okazaki
Publikationsdatum
08.03.2019
Verlag
Springer Berlin Heidelberg
Erschienen in
European Journal of Applied Physiology / Ausgabe 5/2019
Print ISSN: 1439-6319
Elektronische ISSN: 1439-6327
DOI
https://doi.org/10.1007/s00421-019-04118-5

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