Mendes Zambetta Rafaella, Signini Étore De Favari, Catai Aparecida Maria, Santos Thainá Cristina Ramos Dos, Michaliski Eloisa Soares, Nazario Ana Karoline, Ocamoto Gabriela Nagai, Frigieri Gustavo, Russo Thiago Luiz
Physical Therapy Department, Federal University of São Carlos, UFSCar, Rodovia Washington Luís, Km 235, São Carlos, SP, Brazil.
Brain4care Inc, São Carlos, SP, Brazil.
Brain Spine. 2024 Aug 29;4:103327. doi: 10.1016/j.bas.2024.103327. eCollection 2024.
Spaceflights influence intracranial compliance (ICC). P2/P1 ratio, from the intracranial pressure (ICP) waveform, provides information about ICC. Additionally, non-invasive methods for ICC monitoring are needed for spaceflights. Furthermore, astronauts try to maintain good levels of cardiorespiratory fitness before and during spaceflights, not only to sustain exploratory missions, but also to prevent diseases in extreme environments.
to correlate cardiorespiratory fitness levels with the P2/P1 ratio during a microgravity analog [-6° head-down tilt (HDT)].
34 individuals (11 women), mean age of 31.7 (±6.3) years and BMI 24.2 (±3.2) performed a cardiopulmonary exercise testing (CPET) with an incremental protocol on a cycle ergometer to determine the cardiopulmonary fitness through peak relative oxygen uptake (VO peak) of each individual. On the second test, which was conducted in an interval of 15 days of the CPET, participants remained for 30 min at HDT with P2/P1 ratio acquired using a non-invasive strain gauge sensor. The average of the last 5 min was used for analysis. The mean P2/P1 ratio and relative VO peak were correlated using the Spearman test.
Volunteers presented 1.05 ± 0.2 of P2/P1 ratio and VO peak of 47.5 ± 7.6 mL/kg/min. The Spearman test indicated a negative and low correlation between the P2/P1 ratio and VO peak (ρ = -0.388; p = 0.023).
The study suggests that the better the cardiorespiratory fitness, the better ICC in a weightlessness simulation.
太空飞行会影响颅内顺应性（ICC）。颅内压（ICP）波形中的P2/P1比值可提供有关ICC的信息。此外，太空飞行需要用于ICC监测的非侵入性方法。此外，宇航员在太空飞行之前和期间试图保持良好的心肺适能水平，不仅是为了维持探索任务，也是为了预防极端环境中的疾病。
在微重力模拟[-6°头低位倾斜（HDT）]期间，将心肺适能水平与P2/P1比值相关联。
34名个体（11名女性），平均年龄31.7（±6.3）岁，体重指数24.2（±3.2），在功率自行车上按照递增方案进行心肺运动测试（CPET），通过每个人的峰值相对摄氧量（VO峰值）来确定心肺适能。在CPET后15天的间隔内进行的第二次测试中，参与者在HDT状态下保持30分钟，使用非侵入性应变片传感器获取P2/P1比值。使用最后5分钟的平均值进行分析。使用Spearman检验将平均P2/P1比值与相对VO峰值进行关联。
志愿者的P2/P1比值为1.05±0.2，VO峰值为47.5±7.6 mL/kg/min。Spearman检验表明P2/P1比值与VO峰值之间存在负向且低强度的相关性（ρ = -0.388；p = 0.023）。
该研究表明，在失重模拟中，心肺适能越好，ICC越好。
