间断性短臂离心机＋Gz暴露联合运动锻炼对心血管自主神经调节功能的影响

Effects of Intermittent Short-arm Centrifuge Training with Exercise on Cardiovascular Autonomic Regulation Function

目的利用短臂离心机进行梯度G值联合运动负荷锻炼,观察间断性锻炼3周后人体心血管自主神经调节功能的变化。方法8名健康青年男性间断进行离心机梯度G值(1～2G)暴露联合30W运动负荷锻炼,每天30min,持续3周。记录心电图和逐跳连续血压,运用自回归谱分析法得到心率变异性(HRV)与收缩压变异性功率谱。锻炼前后进行头高位倾斜联合下体负压测试,观察立位应激时心血管功能变化。结果在卧位休息时,锻炼3周后被试者HRV的低频与高频比值较锻炼前显著下降(P<0.05),收缩压变异性的低频功率较锻炼前显著增加(P<0.05)。在头高位倾斜联合下体负压实验时,锻炼后被试者心率较锻炼前显著下降(P<0.05),总外周阻力显著增加(P<0.05),每搏量呈增加的趋势。结论离心机+Gz暴露联合30W运动锻炼3周可以增加平卧位心脏迷走神经与外周血管交感神经活动水平,增强立位应激时血压调节能力,提高了心血管功能储备。

Objective To evaluate the change of cardiovascular autonomic regulation function during 3 weeks training of intermittent short arm centrifuge graded （ 1 -2 G） ＋ Gz loading with exercise. Methods During 3 weeks experiment, 8 healthy ambulatory men were under intermittent graded ＋ Gz centrifuge loading with 30 W ergonometer exercise for 30 min everyday. The ECG and beat by beat blood pressure were non-invasively recorded. Heart rate variability and systolic blood pressure variability were analyzed using auto regression method. Pre- and post-training, cardiovascular function was evaluated using head up tilt test （HUT） and low body negative pressure （LBNP） as an orthostatic stress. Results During supine position, heart rate spectral analysis showed that the power ratio of low to high frequency components was significantly declined （P 〈 0.05 ） after 3 weeks training, while systolic blood pressure analysis showed that the low frequency components increased significantly （P 〈 0.05 ）. During HUT and LBNP, heart rate after training decreased significantly （ P 〈 0.05 ） while total peripheral resistance increased （ P 〈 0.05 ） , when compared with those of before training. Stroke volume had a tendency to increase. Conclusion The results of the present study suggest that 3 weeks combination training of intermittent graded ＋ Gz loading with 30 W exercise might induce an increase in cardiac vagal modulation and peripheral vascular sympathetic response, as well as might enhance blood pressure regulation and cardiac function during orthostatic stress.