From the Departments of Health and Human Physiology (L.E.D., L.R., G.L.P.).
Radiology (L.L.B.P.).
Hypertension. 2018 Aug;72(2):476-482. doi: 10.1161/HYPERTENSIONAHA.118.11143. Epub 2018 Jun 18.
Greater aortic stiffness and pulse pressure are associated with cerebrovascular remodeling, reduced white matter microstructure, and cognitive performance with aging in humans. However, it is unclear whether aortic stiffness and pulse pressure are associated with reduced basal global cerebral blood flow (CBF) and cerebrovascular reserve among older adults. Global CBF was quantified in 205 adults (range, 19-87 years; mean±SE: 30.6±1.3 years) using quantitative [O]water brain positron emission tomography imaging. In a subset of older adults (n=24; 70.0±2.0 years), aortic stiffness (carotid femoral pulse wave velocity) and cerebrovascular reserve (change in global CBF after intravenous infusion of acetazolamide) were assessed. In the entire cohort, global CBF was lower in older compared with young adults (36.5±1.1 versus 50.5±0.7 mL/min per 100 mL; <0.001). Global CBF was higher in young women compared with young men (51.0±0.30 versus 47.4±0.03 mL/min per 100 mL; <0.001) but did not differ between older women and men (=0.63). In older adults, greater carotid femoral pulse wave velocity was associated with lower cerebrovascular reserve (=-0.68; =0.001 adjusted for age, sex, and mean arterial pressure) but not global CBF (=0.13; =0.60). Brachial pulse pressure was not associated with lower cerebrovascular reserve (=-0.37; =0.159) when adjusted for age and sex. These data indicate that the age-related increases in aortic stiffness may contribute, in part, to the brain's impaired ability to augment blood flow in response to a stimulus with aging in humans.
主动脉僵硬度和脉搏压的增加与脑血管重塑、白质微观结构减少以及老年人认知能力下降有关。然而，目前尚不清楚主动脉僵硬度和脉搏压是否与老年人基础全脑血流（CBF）减少和脑血管储备能力降低有关。使用定量[O]水脑正电子发射断层扫描成像对 205 名成年人（年龄范围 19-87 岁；平均±SE：30.6±1.3 岁）的全脑 CB 进行了量化。在一组老年人（n=24；70.0±2.0 岁）中，评估了主动脉僵硬度（颈股脉搏波速度）和脑血管储备（静脉注射乙酰唑胺后全脑 CBF 的变化）。在整个队列中，与年轻人相比，老年人的全脑 CBF 较低（36.5±1.1 与 50.5±0.7 mL/min/100 mL；<0.001）。年轻女性的全脑 CBF 高于年轻男性（51.0±0.30 与 47.4±0.03 mL/min/100 mL；<0.001），但老年女性和男性之间没有差异（=0.63）。在老年人中，颈股脉搏波速度越大，脑血管储备越低（=-0.68；年龄、性别和平均动脉压校正后=0.001），但全脑 CBF 无差异（=0.13；=0.60）。调整年龄和性别后，肱动脉脉搏压与较低的脑血管储备无关（=-0.37；=0.159）。这些数据表明，主动脉僵硬度的年龄相关性增加可能部分导致人类大脑随着年龄的增长，在应对刺激时增加血流的能力受损。
