Millar Philip J, Rakobowchuk Mark, Adams Melanie M, Hicks Audrey L, McCartney Neil, MacDonald Maureen J
Department of Kinesiology, McMaster University, 1280 Main Street W., Hamilton, Ontario, Canada.
Auton Neurosci. 2009 Oct 5;150(1-2):116-21. doi: 10.1016/j.autneu.2009.03.012. Epub 2009 Apr 29.
Increased risk of cardiovascular diseases and autonomic dysregulation are common health concerns in individuals with spinal cord injury (SCI). Two therapies that may help improve cardiovascular control are body-weight supported treadmill training (BWSTT) and head-up tilt training (HUTT). The purpose of this study was to examine the effects of short-term BWSTT and HUTT on cardiac autonomic function. Seven participants (6 male, 37.1+/-7.7 years) with SCI (C5-T10, ASIA A-C; 5.0+/-4.4 years post-injury) completed the study protocol. In this randomized cross-over design, participants were required to complete 4 weeks of thrice-weekly BWSTT and HUTT (i.e. 12 sessions each), separated by a 4 week detraining period. Cardiac autonomic function was assessed at rest, before and after, each 4 week training period using linear and non-linear measures (sample entropy and detrended fluctuation analysis (alpha(1))) of heart rate dynamics. Participants completed equivalent amounts of time performing BWSTT and HUTT (453.7+/-27.3 min vs. 471.6+/-19.7 min, p=0.24). There were no significant differences in linear heart rate variability following BWSTT or HUTT (p>0.05). In contrast, there was a significant change in sample entropy following BWSTT (1.05+/-0.14 to 1.42+/-0.12, p<0.05). Due to the bi-directional pattern of alpha(1) values, distance scores were calculated (|1-alpha(1)|) and demonstrated a significant reduction following BWSTT (0.54+/-0.06 to 0.26+/-0.05, p=0.001). In conclusion, 4 weeks of BWSTT but not HUTT training are sufficient to increase sample entropy and reduce the fractal scaling distance score in participants with SCI.
心血管疾病风险增加和自主神经调节异常是脊髓损伤（SCI）患者常见的健康问题。体重支持跑步机训练（BWSTT）和头高位倾斜训练（HUTT）这两种疗法可能有助于改善心血管控制。本研究的目的是探讨短期BWSTT和HUTT对心脏自主神经功能的影响。七名脊髓损伤患者（6名男性，年龄37.1±7.7岁）（损伤节段C5 - T10，美国脊髓损伤协会分级A - C；损伤后5.0±4.4年）完成了研究方案。在这个随机交叉设计中，参与者需要完成4周每周三次的BWSTT和HUTT训练（即各12次训练），中间间隔4周的去训练期。在每个4周训练期的前后，使用心率动态的线性和非线性测量指标（样本熵和去趋势波动分析（α(1)））在静息状态下评估心脏自主神经功能。参与者进行BWSTT和HUTT的时间量相当（453.7±27.3分钟对471.6±19.7分钟，p = 0.24）。BWSTT或HUTT训练后线性心率变异性无显著差异（p>0.05）。相比之下，BWSTT训练后样本熵有显著变化（从1.05±0.14变为1.42±0.12，p<0.05）。由于α(1)值的双向模式，计算了距离分数（|1 - α(1)|），结果显示BWSTT训练后显著降低（从0.54±0.06降至0.26±0.05，p = 0.001）。总之，4周的BWSTT训练而非HUTT训练足以增加脊髓损伤患者的样本熵并降低分形标度距离分数。
