Regional cerebral autoregulation during orthostatic stress: Age-related differences
Regional cerebral autoregulation during orthostatic stress: Age-related differences
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DOI：
10.1093/gerona/60.11.1484
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发表时间：
2005-11-01
影响因子：
5.1
通讯作者：
Lipsitz, LA
中科院分区：
文献类型：
--
作者：
Sorond, FA;Khavari, R;Lipsitz, LA
背景我们使用经颅多普勒超声检查脑血流反应的立位应力在中，后脑循环，并确定健康老龄化对局部脑血流调节的影响。连续测量13名年轻（30 ± 7岁）和13名老年（73 ± 4岁）健康受试者的大脑中动脉（MCA）和后动脉（PCA）血流速度（BFV）和平均动脉压（MAP）。年龄较大的受试者在Poetry变化期间MAP下降幅度较大（老年人为-31% +/-3，年轻人为-21% +/-2），心率（HR）增加幅度较小（老年人为15 bpm +/-1，年轻人为24 bpm +/-2）。尽管MAP下降幅度较大，但老年受试者在两个血管区域的BFV下降幅度与年轻受试者非常相似。这与老年受试者MCA和PCA血管区域的血管舒张反应显著更大有关。在年轻的受试者中，脑血管阻力和BFV对直立位的反应没有区域差异。然而，在老年受试者中，与MCA区域相比，PCA的BFV下降明显更大，血管舒张反应更小。健康老龄化与脑血管对直立性低血压的适应性保持相关。然而，在老年人中，PCA区域血流可能更容易在直立应激期间减少灌注。
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.