Liang Yuan, Gao Zi Zhao, Chen Hong Yu, Gao Hong Kui, Qiang Xiao Peng, Wang Jia
Department of Ultrasonic Medicine, Tangdu Hospital, Air Force Medical University, Xi'an, China.
Department of Pathology, School of Basic Medicine and Xijing Hospital, Air Force Medical University, Xi'an, China.
J Ultrasound Med. 2024 Aug;43(8):1441-1448. doi: 10.1002/jum.16467. Epub 2024 May 3.
To evaluate changes in dynamic cerebral autoregulation (CA) during short-term and long-term exposure to high altitude with ultrasonography, and also study the sex differences in the response of CA to altitude.
We assessed the differences in dynamic CA and measured with Doppler ultrasound of the bilateral internal carotid artery (ICA), vertebral artery (VA), and middle cerebral artery (MCA) and the values of basic information within 48 hours and at 2 years after arrival at Tibet in 65 healthy Han young Chinese volunteers, meanwhile, we compared the resistance index (RI) and pulsatility index (PI) of the right MCA at inhale oxygen 8 minutes when a newcomer with 2 years after arrival at Tibet.
With 2 years of altitude exposure, the SaO of all subjects was above 90%, the mean PEF, DAP, and HR values decreased, HGB increased compared within 48 hours in same-gender groups. Comparisons of cerebral hemodynamics between before 2 years and after 2 years within male and female groups, the mean RI and PI values of bilateral MCA after 2 years were significantly higher than before 2 years, at the same time, the mean RI and PI values of bilateral ICA were significant differences (P < .05) between male groups, with regard to female groups, showed that the mean RI and PI values of bilateral VA were significant differences (P < .05). Comparisons of Right MCA hemodynamics between after oxygen uptake 8 minutes and 2 years, the mean RI and PI values were no significant difference within male and female groups (P > .05).
Acute mountain sickness could result from an alteration of dynamic autoregulation of cerebral blood flow, but the impaired autoregulation may be corrected with the extension of time, furthermore, the response of CA to altitude in males and females are different.
采用超声评估短期和长期暴露于高海拔环境下动态脑自动调节（CA）的变化，并研究CA对海拔反应的性别差异。
我们评估了65名健康汉族年轻中国志愿者抵达西藏后48小时内及2年时双侧颈内动脉（ICA）、椎动脉（VA）和大脑中动脉（MCA）的动态CA差异，并用多普勒超声测量，同时比较了初入藏者和入藏2年者吸氧8分钟时右侧MCA的阻力指数（RI）和搏动指数（PI）。
经过2年的海拔暴露，所有受试者的SaO均高于90%，同性别组内，平均呼气峰流速、舒张压和心率值下降，血红蛋白升高。比较男性和女性组内2年前和2年后的脑血流动力学，2年后双侧MCA的平均RI和PI值显著高于2年前，同时，男性组双侧ICA的平均RI和PI值有显著差异（P<0.05），女性组双侧VA的平均RI和PI值有显著差异（P<0.05）。比较吸氧8分钟后和2年时右侧MCA的血流动力学，男性和女性组内平均RI和PI值无显著差异（P>0.05）。
急性高原病可能源于脑血流动态自动调节的改变，但随着时间延长，受损的自动调节可能得到纠正，此外，男性和女性的CA对海拔的反应不同。
