1. The effects of aging on the distribution of cerebral blood flow with postural changes and mild hyperthermia
- Author
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Kosuke Saho, Yuta Suzuki, Eriko Kawai, Kazunobu Okazaki, Hisayo Yokoyama, Daiki Imai, Ryosuke Takeda, Toshiaki Miyagawa, Nooshin Naghavi, Emiko Morita, and Akemi Ota
- Subjects
Adult ,Male ,Aging ,medicine.medical_specialty ,Supine position ,Physiology ,Vertebral artery ,External carotid artery ,Sitting ,elderly ,Body Temperature ,heat stress ,Orthostatic vital signs ,Stress, Physiological ,Physiology (medical) ,medicine.artery ,Internal medicine ,medicine ,Humans ,Orthopedics and Sports Medicine ,Vertebral Artery ,Aged ,Sitting Position ,business.industry ,carotid artery ,orthostatic stress ,Public Health, Environmental and Occupational Health ,Hyperthermia, Induced ,General Medicine ,Blood flow ,Carotid Arteries ,Cerebral blood flow ,Cerebrovascular Circulation ,Standing Position ,Cardiology ,Internal carotid artery ,business - Abstract
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. 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. With heat stress, ECA blood flow increased in both postures in both age groups (effect of heat, p
- Published
- 2019