Centre for Heart, Lung and Vascular Health, University of British Columbia Okanagan , Kelowna, British Columbia , Canada.
Faculty of Medicine, University of Novi Sad, Novi Sad, Serbia.
Am J Physiol Heart Circ Physiol. 2019 Mar 1;316(3):H722-H733. doi: 10.1152/ajpheart.00693.2018. Epub 2018 Dec 21.
Cardiovascular diseases (CVD) are highly prevalent in spinal cord injury (SCI), and peripheral vascular dysfunction might be a contributing factor. Recent evidence demonstrates that exposure to heat stress can improve vascular function and reduce the risk of CVD in uninjured populations. We therefore aimed to examine the extent of vascular dysfunction in SCI and the acute effects of passive heating. Fifteen participants with cervical SCI and 15 uninjured control (CON) participants underwent ultrasound assessments of vascular function and venous blood sampling for biomarkers of endothelial activation (i.e., CD62e) and apoptosis (i.e., CD31/42b) before and after a 60-min exposure to lower limb hot water immersion (40°C). In SCI, macrovascular endothelial function was reduced in the brachial artery [SCI: 4.8 (3.2)% vs. CON: 7.6 (3.4)%, P = 0.04] but not the femoral artery [SCI: 3.7 (2.6)% vs. CON: 4.0 (2.1)%, P = 0.70]. Microvascular function, via reactive hyperemia, was ~40% lower in SCI versus CON in both the femoral and brachial arteries ( P < 0.01). Circulating concentrations of CD62e were elevated in SCI versus CON [SCI: 152 (106) microparticles/µl vs. CON: 58 (24) microparticles/µl, P < 0.05]. In response to heating, macrovascular and microvascular function remained unchanged, whereas increases (+83%) and decreases (-93%) in antegrade and retrograde shear rates, respectively, were associated with heat-induced reductions of CD62e concentrations in SCI to levels similar to CON ( P = 0.05). These data highlight the potential of acute heating to provide a safe and practical strategy to improve vascular function in SCI. The chronic effects of controlled heating warrant long-term testing. NEW & NOTEWORTHY Individuals with cervical level spinal cord injury exhibit selectively lower flow-mediated dilation in the brachial but not femoral artery, whereas peak reactive hyperemia was lower in both arteries compared with uninjured controls. After 60 min of lower limb hot water immersion, femoral artery blood flow and shear patterns were acutely improved in both groups. Elevated biomarkers of endothelial activation in the spinal cord injury group decreased with heating, but these biomarkers remained unchanged in controls.
心血管疾病（CVD）在脊髓损伤（SCI）中非常普遍，外周血管功能障碍可能是一个促成因素。最近的证据表明，暴露于热应激下可以改善血管功能并降低未受伤人群患 CVD 的风险。因此，我们旨在检查 SCI 中血管功能障碍的程度以及被动加热的急性影响。15 名颈段 SCI 参与者和 15 名未受伤对照组（CON）参与者在接受 60 分钟下肢热水浸泡（40°C）之前和之后，接受了血管功能超声评估和静脉血采样，以检测内皮激活（即 CD62e）和细胞凋亡（即 CD31/42b）的生物标志物。在 SCI 中，肱动脉的大血管内皮功能降低[SCI：4.8（3.2）% vs. CON：7.6（3.4）%，P=0.04]，但股动脉无变化[SCI：3.7（2.6）% vs. CON：4.0（2.1）%，P=0.70]。通过反应性充血，SCI 中股动脉和肱动脉的微血管功能比 CON 低约 40%（P<0.01）。与 CON 相比，SCI 中 CD62e 的循环浓度升高[SCI：152（106）微粒/µl vs. CON：58（24）微粒/µl，P<0.05]。对加热的反应中，肱动脉和股动脉的大血管和微血管功能保持不变，而正向和逆向剪切率分别增加（+83%）和减少（-93%）与 SCI 中 CD62e 浓度的热诱导降低相关，使其达到与 CON 相似的水平（P=0.05）。这些数据强调了急性加热提供安全实用的策略来改善 SCI 中血管功能的潜力。受控加热的慢性影响需要进行长期测试。新观点和值得注意的是：颈段脊髓损伤的个体在肱动脉中表现出选择性较低的血流介导扩张，而在股动脉中，峰值反应性充血也较低，与未受伤对照组相比。在下肢热水浸泡 60 分钟后，两组的股动脉血流和剪切模式均得到急性改善。脊髓损伤组中升高的内皮激活生物标志物随着加热而降低，但对照组中的这些生物标志物没有变化。
