TY - JOUR
T1 - Regional cerebral autoregulation during orthostatic stress
T2 - Age-related differences
AU - Sorond, Farzaneh A.
AU - Khavari, Rose
AU - Serrador, Jorge M.
AU - Lipsitz, Lewis A.
PY - 2005/11
Y1 - 2005/11
N2 - Background. We used transcranial Doppler ultrasonography to examine the cerebral blood flow response to orthostatic stress in the middle and posterior cerebral circulations and to determine the effects of healthy aging on regional cerebral blood flow regulation. Methods. Continuous simultaneous middle (MCA) and posterior (PCA) cerebral artery blood flow velocities (BFV) and mean arterial pressure (MAP) were measured in response to standing from a sitting position in 13 younger (30 ± 7 years) and 13 older (73 ± 4 years) healthy participants. Results. The older participants had a significantly larger decline in MAP (-31% ± 3 in the older and -21% ± 2 in the younger) and a smaller increase in heart rate (HR) (15 bpm ± 1 in the older. 24 bpm ± 2 in the younger) during the posture change. Despite a larger decline in MAP, the older participants had a decline very similar to that of the younger participants in BFVs in both vascular territories. This was associated with a significantly larger vasodilatory response in the MCA and PCA vascular territories of the older participants. There were no regional differences of the cerebrovascular resistance and BFV responses to orthostasis in the younger participants. However, in the older participants, there was a significantly larger BFV decline and a smaller vasodilatory response in the PCA as compared to the MCA territory. Conclusions. Healthy aging is associated with preserved cerebrovascular adaptation to orthostatic hypotension. However, in older persons, the PCA territory blood flow may be more vulnerable to reduced perfusion during orthostatic stress.
AB - Background. We used transcranial Doppler ultrasonography to examine the cerebral blood flow response to orthostatic stress in the middle and posterior cerebral circulations and to determine the effects of healthy aging on regional cerebral blood flow regulation. Methods. Continuous simultaneous middle (MCA) and posterior (PCA) cerebral artery blood flow velocities (BFV) and mean arterial pressure (MAP) were measured in response to standing from a sitting position in 13 younger (30 ± 7 years) and 13 older (73 ± 4 years) healthy participants. Results. The older participants had a significantly larger decline in MAP (-31% ± 3 in the older and -21% ± 2 in the younger) and a smaller increase in heart rate (HR) (15 bpm ± 1 in the older. 24 bpm ± 2 in the younger) during the posture change. Despite a larger decline in MAP, the older participants had a decline very similar to that of the younger participants in BFVs in both vascular territories. This was associated with a significantly larger vasodilatory response in the MCA and PCA vascular territories of the older participants. There were no regional differences of the cerebrovascular resistance and BFV responses to orthostasis in the younger participants. However, in the older participants, there was a significantly larger BFV decline and a smaller vasodilatory response in the PCA as compared to the MCA territory. Conclusions. Healthy aging is associated with preserved cerebrovascular adaptation to orthostatic hypotension. However, in older persons, the PCA territory blood flow may be more vulnerable to reduced perfusion during orthostatic stress.
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U2 - 10.1093/gerona/60.11.1484
DO - 10.1093/gerona/60.11.1484
M3 - Article
C2 - 16339339
AN - SCOPUS:29144432724
VL - 60
SP - 1484
EP - 1487
JO - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
JF - Journals of Gerontology - Series A Biological Sciences and Medical Sciences
SN - 1079-5006
IS - 11
ER -