Older Age and Male Sex are Associated with Higher Cerebrovascular Impedance.
Older Age and Male Sex are Associated with Higher Cerebrovascular Impedance.
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DOI：
10.1152/japplphysiol.00396.2020
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发表时间：
2020-11
影响因子：
3.3
通讯作者：
J. Sugawara;T. Tarumi;Changyang Xing;Jie Liu;Tsubasa Tomoto;Evan P Pasha;Rong Zhang
中科院分区：
文献类型：
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作者：
J. Sugawara;T. Tarumi;Changyang Xing;Jie Liu;Tsubasa Tomoto;Evan P Pasha;Rong Zhang
脑血流（CBF）响应于灌注压的脉动变化而变得脉动，灌注压的脉动变化由脑血管阻抗调节。在这项研究中，我们的目的是表征年龄相关的脑血管阻抗的差异在整个成人寿命。对148例健康成人（21-79岁，62%为女性）进行颈动脉压（CAP）和大脑中动脉血流速度（CBFV）的测定。采用传递函数分析法对脑血管阻抗进行定量。在0.78- 2.73Hz频率范围内，CBFV与CAP变化的相关性大于0.90，两者呈线性动态关系。主要反映心率频率的CBFV和CAP振荡的一次谐波处的阻抗模量（Z1，0.78-1.56 Hz）在老年人（> 64岁，P=0.002）中比年轻人（<45岁）高20%，在中年人（45-64岁，P=0.08）中比年轻人（<45岁）高13%。此外，男性的Z1比女性高24%（P<0.001）。多元线性回归分析显示，校正年龄、性别和体重指数（BMI）后，Z1与收缩压（β =-0.470）、舒张压（β =-0.418）、搏动压（β =-0.374）和平均CBFV（β=-0.473）呈负相关（均P<0.001）。这些结果表明，年龄较大和男性与较高的脑血管阻抗比年轻人，这可能有助于脑灌注不足。
Cerebral blood flow (CBF) becomes pulsatile in response to pulsatile change in perfusion pressure which is regulated by cerebrovascular impedance. In this study, we aimed to characterize age-related differences in cerebrovascular impedance across the adult lifespan. Carotid artery pressure (CAP, via applanation tonometry) and CBF velocity in the middle cerebral artery (CBFV, via transcranial Doppler) were measured in 148 healthy adults (21-79 years, 62% women). Cerebrovascular impedance was quantified using transfer function analysis. Coherence between changes in CBFV and CAP was higher than 0.90 in the frequency range of 0.78-2.73 Hz, suggesting linear dynamic relationship between these two variables. Impedance modulus at the first harmonics of CBFV and CAP oscillations (Z1, 0.78-1.56 Hz), reflected mainly heart rate frequency, was 20 % higher in the old (> 64 years, P=0.002) and 13 % higher in the middle-aged (45-64 years, P=0.08) than young individuals (<45 years). In addition, Z1 was 24% higher in men than women (P<0.001). Multiple linear regression analysis revealed that Z1 is negatively associated with systolic (β=-0.470), diastolic (β=-0.418), pulsatile (β=-0.374), and mean CBFV (β=-0.473) (P<0.001 for all) after adjustment for age, sex, and body mass index (BMI). These results suggest that older age and male sex are associated with higher cerebrovascular impedance than young individuals which may contribute to brain hypoperfusion.