German Aerospace Center - DLR, Institute of Aerospace Medicine, Linder Hoehe, 51147, Cologne, Germany.
Department of Internal Medicine III, Division of Cardiology, Pneumology, Angiology, and Intensive Care, University of Cologne, Kerpener Str. 62, 50937, Cologne, Germany.
Clin Auton Res. 2023 Aug;33(4):401-410. doi: 10.1007/s10286-023-00959-5. Epub 2023 Jun 22.
Orthostatic intolerance commonly occurs following immobilization or space flight. We hypothesized that daily artificial gravity training through short-arm centrifugation could help to maintain orthostatic tolerance following head-down tilt bedrest, which is an established terrestrial model for weightlessness.
We studied 24 healthy persons (eight women; age 33.3 ± 9.0 years; BMI 24.3 ± 2.1 kg/m) who participated in the 60-days head-down tilt bedrest (AGBRESA) study. They were assigned to 30 min/day continuous or 6 × 5 min intermittent short-arm centrifugation with 1Gz at the center of mass or a control group. We performed head-up tilt testing with incremental lower-body negative pressure until presyncope before and after bedrest. We recorded an electrocardiogram, beat-to-beat finger blood pressure, and brachial blood pressure and obtained blood samples from an antecubital venous catheter. Orthostatic tolerance was defined as time to presyncope. We related changes in orthostatic tolerance to changes in plasma volume determined by carbon dioxide rebreathing.
Compared with baseline measurements, supine and upright heart rate increased in all three groups following head-down tilt bedrest. Compared with baseline measurements, time to presyncope decreased by 323 ± 235 s with continuous centrifugation, by 296 ± 508 s with intermittent centrifugation, and by 801 ± 354 s in the control group (p = 0.0249 between interventions). The change in orthostatic tolerance was not correlated with changes in plasma volume.
Daily artificial gravity training on a short-arm centrifuge attenuated the reduction in orthostatic tolerance after 60 days of head-down tilt bedrest.
体位不耐受通常发生在固定或太空飞行之后。我们假设，通过短臂离心机进行日常人工重力训练可以帮助维持头低位卧床休息后的体位耐受力，这是一种建立在失重基础上的地面模型。
我们研究了 24 名健康人（8 名女性；年龄 33.3±9.0 岁；BMI 24.3±2.1kg/m），他们参加了为期 60 天的头低位卧床休息（AGBRESA）研究。他们被分为连续 30 分钟/天或 6×5 分钟间歇性短臂离心机，在质心处产生 1Gz 的重力或对照组。我们在卧床休息前后进行头高位倾斜测试，通过逐渐降低下半身负压来诱发先兆晕厥。我们记录心电图、逐搏手指血压和肱动脉血压，并从肘前静脉导管采集血液样本。体位耐受力定义为先兆晕厥的时间。我们将体位耐受力的变化与通过二氧化碳再呼吸确定的血浆容量变化相关联。
与基线测量相比，所有三组在头低位卧床休息后，仰卧位和直立位心率均增加。与基线测量相比，连续离心组的先兆晕厥时间减少了 323±235s，间歇离心组减少了 296±508s，对照组减少了 801±354s（干预之间的 p=0.0249）。体位耐受力的变化与血浆容量的变化无关。
短臂离心机上的日常人工重力训练可减轻头低位卧床休息 60 天后体位耐受力的降低。
