Cardiovascular Research Group, School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Perth, AUSTRALIA.
Med Sci Sports Exerc. 2021 Sep 1;53(9):1945-1957. doi: 10.1249/MSS.0000000000002654.
Exercise training has antiatherogenic effects on conduit and resistance artery function and structure in humans and induces angiogenic changes in skeletal muscle. However, training-induced adaptation in cutaneous microvessels is poorly understood, partly because of technological limitations. Optical coherence tomography (OCT) is a novel high-resolution imaging technique capable of visualizing cutaneous microvasculature at a resolution of ~30 μm. We utilized OCT to visualize the effects of training on cutaneous microvessels, alongside assessment of conduit artery flow-mediated dilation (FMD).
We assessed brachial FMD and cutaneous microcirculatory responses at rest and in response to local heating and reactive hyperemia: pretraining and posttraining in eight healthy men compared with age-matched untrained controls (n = 8). Participants in the training group underwent supervised cycling at 80% maximal heart rate three times a week for 8 wk.
We found a significant interaction (P = 0.04) whereby an increase in FMD was observed after training (post 9.83% ± 3.27% vs pre 6.97% ± 1.77%, P = 0.01), with this posttraining value higher compared with the control group (6.9% ± 2.87%, P = 0.027). FMD was not altered in the controls (P = 0.894). There was a significant interaction for OCT-derived speed (P = 0.038) whereby a significant decrease in the local disk heating response was observed after training (post 98.6 ± 3.9 μm·s-1 vs pre 102 ± 5 μm·s-1, P = 0.012), whereas no changes were observed for OCT-derived speed in the control group (P = 0.877). Other OCT responses (diameter, flow rate, and density) to local heating and reactive hyperemia were unaffected by training.
Our findings suggest that vascular adaptation to exercise training is not uniform across all levels of the arterial tree; although exercise training improves larger artery function, this was not accompanied by unequivocal evidence for cutaneous microvascular adaptation in young healthy subjects.
运动训练对人体的输送血管和阻力血管的功能和结构具有抗动脉粥样硬化作用，并诱导骨骼肌的血管生成变化。然而，由于技术限制，对于训练引起的皮肤微血管适应性改变的了解甚少。光学相干断层扫描（OCT）是一种新的高分辨率成像技术，能够以~30μm 的分辨率可视化皮肤微血管。我们利用 OCT 来观察训练对皮肤微血管的影响，同时评估输送血管的血流介导的扩张（FMD）。
我们评估了 8 名健康男性的肱动脉 FMD 和皮肤微循环反应，包括在休息时和局部加热及反应性充血时的反应：在训练前和训练后进行比较，同时还评估了年龄匹配的未经训练对照组（n=8）。训练组的参与者每周进行 3 次、每次 80%最大心率的监督式自行车运动，共 8 周。
我们发现了一个显著的交互作用（P=0.04），即 FMD 在训练后增加（后 9.83%±3.27%比前 6.97%±1.77%，P=0.01），并且这个后训练值高于对照组（6.9%±2.87%，P=0.027）。对照组的 FMD 没有变化（P=0.894）。OCT 衍生的速度也存在显著的交互作用（P=0.038），即训练后局部盘加热反应明显下降（后 98.6±3.9μm·s-1比前 102±5μm·s-1，P=0.012），而对照组的 OCT 衍生速度没有变化（P=0.877）。其他 OCT 反应（直径、血流率和密度）对局部加热和反应性充血没有受到训练的影响。
我们的发现表明，运动训练引起的血管适应性在动脉树的所有水平上并不均匀；尽管运动训练改善了较大动脉的功能，但在年轻健康受试者中，这并没有伴随着皮肤微血管适应性的明确证据。
