Supporting data for ''Cardiac-Hematological Capacity in Healthy Hans Chinese: Effects of Blood Volume and Body Composition''

Cardiac output (Q) is essential to the assessment of cardiac function and the diagnosis of various heart diseases. Peak cardiac output (Qpeak) elicited by incremental exercise to peak effort, represents cardiac capacity. Qpeak strongly predicts maximal oxygen uptake (VO2max) as well as mortality. Endurance training induces significant increases in VO2max. Despite of similar exercise stimuli, women tend to improve less in cardiovascular adaptations compared with men. One possible reason is that women have smaller heart compared with men and the pericardium may limit the expansion of the left ventricle (LV) during peak exercise, thus the cardiac adaptation is limited. In chapter 1, the ambient pressure driving venous return during incremental exercise was manipulated in women and men, revealing that the female young heart is unrestrained by venous return or structural factors external to the myocardium.Blood volume (BV) facilitates venous return, cardiac filling and output, determining aerobic capacity. Despite women are endowed with lower blood-oxygen carrying capacity, women and men presented similar VO2max after normalization by lean body mass (LBM). LBM is strongly and exclusively associated with aerobic capacity in women, independent of body fat percentage. In chapter 2, whether aerobic capacity and its biological determinants including blood volume and body composition are ethnic-specific were investigated in a well-characterized corhort of Hans Chinese (HC) and European-American (EA) individuals.LBM and the functional capacity of the cardiovascular system constitute a female-specific relationship in EA individuals. In chapter 3, whether such finding can be extrapolated to HC, a population characterized by low LBM was explored. Overall, this study eliminated the knowledge gaps in contemporary human physiology regarding main determinants of cardiorespiratory fitness, potentially translating to improve or preserve cardiovascular health in a large fraction of the population.

心输出量（Q）对于评估心脏功能及诊断各种心脏病至关重要。由递增运动至峰值努力所诱发的峰值心输出量（Qpeak）代表了心脏的容量。Qpeak强烈预示着最大摄氧量（VO2max）及死亡率。耐力训练可显著提高VO2max。尽管面临相似的锻炼刺激，女性在心血管适应性方面的改善通常不及男性。可能的原因之一是女性的心脏较男性较小，且心包在峰值运动期间可能限制左心室（LV）的扩张，从而限制了心脏的适应性。在第1章中，通过操纵女性和男性在递增运动期间驱动静脉回流的周围压力，揭示了女性年轻心脏不受静脉回流或心肌外部结构因素的影响。血容量（BV）促进了静脉回流、心脏充盈和输出，决定了有氧能力。尽管女性的携氧能力较低，但在通过瘦体重（LBM）进行标准化后，女性和男性的VO2max表现相似。LBM与女性的有氧能力强相关，且独立于体脂百分比。在第2章中，研究调查了有氧能力及其生物决定因素，包括血容量和身体成分是否具有种族特异性，研究对象为特征明确的汉族（HC）和欧洲裔美国人（EA）个体。在EA个体中，LBM和心血管系统的功能性能力构成了女性特有的关系。在第3章中，探讨了上述发现是否可以外推至HC，一个以低LBM为特征的人群。总体而言，本研究消除了当代人体生理学中关于主要心肺健康决定因素的知识空白，有望为大量人群改善或维持心血管健康。