Kourtidou-Papadeli Chrysoula, Frantzidis Christos A, Gilou Sotiria, Plomariti Christina E, Nday Christiane M, Karnaras Dimitrios, Bakas Lefteris, Bamidis Panagiotis D, Vernikos Joan
Biomedical Engineering & Aerospace Neuroscience, Laboratory of Medical Physics, Faculty of Health Sciences, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Greek Aerospace Medical Association and Space Research, Thessaloniki, Greece.
Front Physiol. 2021 May 11;12:644661. doi: 10.3389/fphys.2021.644661. eCollection 2021.
Increasing the level of gravity passively on a centrifuge, should be equal to or even more beneficial not only to astronauts living in a microgravity environment but also to patients confined to bed. Gravity therapy (GT) may have beneficial effects on numerous conditions, such as immobility due to neuromuscular disorders, balance disorders, stroke, sports injuries. However, the appropriate configuration for administering the Gz load remains to be determined.
To address these issues, we studied graded G-loads from 0.5 to 2.0g in 24 young healthy, male and female participants, trained on a short arm human centrifuge (SAHC) combined with mild activity exercise within 40-59% MHR, provided by an onboard bicycle ergometer. Hemodynamic parameters, as cardiac output (CO), stroke volume (SV), mean arterial pressure (MAP), systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were analyzed, as well as blood gas analysis. A one-way repeated measures ANOVA and pairwise comparisons were conducted with a level of significance < 0.05.
Significant changes in heart rate variability (HRV) and its spectral components (Class, Fmax, and VHF) were found in all g loads when compared to standing ( < 0.001), except in 1.7 and 2.0g. There were significant changes in CO, cardiac index (CI), and cardiac power (CP) ( < 0.001), and in MAP ( = 0.003) at different artificial gravity (AG) levels. Dose-response curves were determined based on statistically significant changes in cardiovascular parameters, as well as in identifying the optimal G level for training, as well as the optimal G level for training. There were statistically significant gender differences in Cardiac Output/CO ( = 0.002) and Cardiac Power/CP ( = 0.016) during the AG training as compared to standing. More specifically, these cardiovascular parameters were significantly higher for male than female participants. Also, there was a statistically significant ( = 0.022) gender by experimental condition interaction, since the high-frequency parameter of the heart rate variability was attenuated during AG training as compared to standing but only for the female participants ( = 0.004).
The comprehensive cardiovascular evaluation of the response to a range of graded AG loads, as compared to standing, in male and female subjects provides the dose-response framework that enables us to explore and validate the usefulness of the centrifuge as a medical device. It further allows its use in precisely selecting personalized gravity therapy (GT) as needed for treatment or rehabilitation of individuals confined to bed.
在离心机上被动增加重力水平，不仅应对生活在微重力环境中的宇航员有益，对卧床患者也应同样有益甚至更有益。重力疗法（GT）可能对多种病症有有益影响，如神经肌肉疾病导致的活动受限、平衡障碍、中风、运动损伤等。然而，施加Gz负荷的合适配置仍有待确定。
为解决这些问题，我们对24名年轻健康的男性和女性参与者进行了研究，让他们在短臂人体离心机（SAHC）上接受0.5至2.0g的分级G负荷训练，并结合由车载自行车测力计提供的40 - 59%最大心率（MHR）的轻度活动锻炼。分析了血流动力学参数，如心输出量（CO）、每搏输出量（SV）、平均动脉压（MAP）、收缩压（SBP）、舒张压（DBP）和心率（HR），以及血气分析。进行了单因素重复测量方差分析和两两比较，显著性水平<0.05。
与站立时相比，除1.7g和2.0g外，所有重力负荷下心率变异性（HRV）及其频谱成分（类别、Fmax和甚高频）均有显著变化（<0.001）。在不同人工重力（AG）水平下，心输出量（CO）、心脏指数（CI）和心脏功率（CP）有显著变化（<0.001），平均动脉压（MAP）有显著变化（=0.003）。根据心血管参数的统计学显著变化确定了剂量反应曲线，以及确定训练的最佳G水平。与站立相比，在AG训练期间，心输出量/CO（=0.002）和心脏功率/CP（=0.016）存在统计学显著的性别差异。更具体地说，男性参与者的这些心血管参数显著高于女性参与者。此外，存在统计学显著的（=0.022）性别与实验条件交互作用，因为与站立相比，AG训练期间心率变异性的高频参数仅在女性参与者中减弱（=0.004）。
与站立相比，对男性和女性受试者在一系列分级AG负荷下的反应进行全面的心血管评估，提供了剂量反应框架，使我们能够探索和验证离心机作为医疗设备的有用性。它还允许根据需要精确选择个性化重力疗法（GT）用于卧床个体的治疗或康复。
