Abstract

Introduction

Individuals show robust resilience and vulnerability in neurobehavioral performance to sleep loss and stress. For the first time, we investigated the time course of two cardiovascular measurements, stroke volume (SV) and cardiac index (CI), both derived from echocardiography, across baseline, total sleep deprivation (TSD), the combination of TSD+psychological stress, and recovery. We also determined whether these variables differ in resilient vs. vulnerable individuals and whether they predict differential vulnerability in cognitive performance.

Methods

Thirty-one healthy adults (ages 27–53; mean±SD, 35.4±7.1y; 14 females) participated in a five-day experiment consisting of two 8h time-in-bed (TIB) baseline nights, 39h TSD, and two 8h-10h TIB recovery nights. A modified Trier Social Stress Test (TSST) was conducted on the TSD day to induce psychological stress. Echocardiographic measures of SV and CI were obtained at six time points (pre-study, baseline, during TSD, during TSD after the TSST, after recovery, and post-study). A median split of TSD performance [total lapses (>500 ms response time) and errors] on the 10-minute Psychomotor Vigilance Test (PVT), defined cognitively resilient (n=15) and vulnerable (n=16) groups. Repeated measures ANOVA and post-hoc comparisons corrected for multiple testing, examined SV and CI across time points between groups.

Results

There was a significant time*group interaction for SV: cognitively resilient individuals had greater SV during the five-day experiment. In addition, in both resilient and vulnerable individuals, SV increased with TSD and with TSD+psychological stress compared with baseline. Like SV, there was a significant time*group interaction for CI: resilient individuals had greater CI at all points of the experiment.

Conclusion

SV and CI differed between resilient and vulnerable individuals across TSD, psychological stress and recovery sleep. Greater SV and greater CI at baseline predicted resilience to TSD and TSD+psychological stress. CI and SV are novel physiological biomarkers of sleep loss, stress, and individual differences in cognitive performance.

Support

NASA NNX14AN49G.

中文翻译：

---

0042中风和弱势个体的总睡眠剥夺和心理压力会不同地改变中风量和心脏指数，并预测认知能力

摘要

介绍

个人表现出强大的适应能力，并且在神经行为表现方面对睡眠丧失和压力的抵抗力强。我们首次调查了两次心血管测量的时程，分别来自超声心动图，基线时的总搏动量（SVD）和心脏指数（CI），总睡眠剥夺（TSD），TSD +心理压力的组合，和恢复。我们还确定了这些变量在有弹性的人群和易受伤害的人群中是否有所不同，以及它们是否预测认知能力的差异性。

方法

31名健康成年人（27-53岁；平均±SD，35.4±7.1y； 14名女性）参加了一个为期五天的实验，其中包括两个8h卧床基线时间，39h TSD和两个8h-10h TIB恢复之夜。在TSD日进行了改良的Trier社会压力测试（TSST），以诱发心理压力。在六个时间点（研究前，基线，TSD期间，TSST之后的TSD期间，恢复后和研究后）获得SV和CI的超声心动图测量值。在10分钟的心理运动警惕性测试（PVT）上，TSD表现的中位数分为[总失误（> 500 ms响应时间）和错误]，定义为认知弹性（n = 15）和脆弱（n = 16）组。重复测量的方差分析和事后比较已针对多项测试进行了校正，检查了两组之间跨时间点的SV和CI。

结果

SV存在显着的时间*群体互动：在五天的实验中，具有认知弹性的个体的SV更高。此外，与基线相比，在有弹性和脆弱的个体中，TSD和TSD +心理压力都使SV升高。像SV一样，CI的时间*群体互动也很明显：有弹性的个体在实验的所有点上都具有更高的CI。

结论

在TSD，心理压力和恢复睡眠方面，适应力强和脆弱的个体之间的SV和CI不同。基线时较高的SV和较高的CI可以预测对TSD和TSD +心理压力的适应力。CI和SV是睡眠丧失，压力和认知能力个体差异的新颖生理生物标志。

支持

美国宇航局NNX14AN49G。