Climie Rachel E, Wheeler Michael J, Grace Megan, Lambert Elisabeth A, Cohen Neale, Owen Neville, Kingwell Bronwyn A, Dunstan David W, Green Daniel J
Baker Heart and Diabetes Institute, Melbourne, Victoria, Australia.
Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia.
J Appl Physiol (1985). 2018 Dec 1;125(6):1787-1794. doi: 10.1152/japplphysiol.00544.2018. Epub 2018 Sep 6.
Prolonged sitting contributes to cardiovascular disease (CVD) risk. The underlying mechanisms are unknown but may include changes in arterial function and vasoactive mediators. We examined the effects of prolonged unbroken sitting, relative to regular active interruptions to sitting time, on arterial function in adults at increased CVD risk. In a randomized crossover trial, 19 sedentary overweight/obese adults (mean ± SD age 57 ± 12 yr) completed 2 laboratory-based conditions: 5 h uninterrupted sitting (SIT) and 5 h sitting interrupted every 30 min by 3 min of simple resistance activities (SRA). Femoral artery function [flow-mediated dilation (FMD)], blood flow, and shear rate were measured at 0 h, 30 min, 1 h, 2 h, and 5 h. Brachial FMD was assessed at 0 and 5 h. Plasma was collected hourly for measurement of endothelin-1 (ET-1), nitrates/nitrites, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1). There was a significant decline in femoral artery FMD, averaged over 5 h in the SIT condition, relative to SRA ( < 0.001). Plasma ET-1 total area under the curve over 5 h increased in the SIT condition compared with SRA ( = 0.006). There was no significant difference between conditions in femoral or brachial shear rate, brachial FMD, nitrates/nitrites, VCAM-1, or ICAM-1 ( > 0.05 for all). Five hours of prolonged sitting, relative to regular interruptions to sitting time, impaired femoral artery vasodilator function and increased circulating ET-1 in overweight/obese adults. There is the need to build on this evidence beyond acute observations to better understand the potential longer-term vascular-related consequences of prolonged sitting. This is the first study to examine the effect of prolonged sitting on arterial function in adults at increased cardiovascular disease risk. We have shown that 5 h of prolonged sitting, relative to regular interruptions to sitting time, impaired femoral artery vasodilator function and increased circulating endothelin-1 in overweight/obese adults. There is now the need to build on this evidence beyond acute observations to better understand the potential longer-term vascular-related consequences of prolonged sitting.
长时间坐着会增加患心血管疾病（CVD）的风险。其潜在机制尚不清楚，但可能包括动脉功能和血管活性介质的变化。我们研究了与定期主动中断坐姿相比，长时间不间断坐着对心血管疾病风险增加的成年人动脉功能的影响。在一项随机交叉试验中，19名久坐的超重/肥胖成年人（平均±标准差年龄57±12岁）完成了2种基于实验室的情况：5小时不间断坐着（SIT）和5小时坐着，每30分钟被3分钟的简单阻力活动（SRA）中断。在0小时、30分钟、1小时、2小时和5小时测量股动脉功能[血流介导的扩张（FMD）]、血流量和剪切率。在0小时和5小时评估肱动脉FMD。每小时采集血浆，用于测量内皮素-1（ET-1）、硝酸盐/亚硝酸盐、血管细胞粘附分子-1（VCAM-1）和细胞间粘附分子-1（ICAM-1）。与SRA相比，SIT条件下5小时的股动脉FMD平均显著下降（<0.001）。与SRA相比，SIT条件下5小时内血浆ET-1曲线下总面积增加（=0.006）。在股动脉或肱动脉剪切率、肱动脉FMD、硝酸盐/亚硝酸盐、VCAM-1或ICAM-1方面，两种情况之间没有显著差异（所有均>0.05）。与定期中断坐姿相比，5小时的长时间坐着会损害超重/肥胖成年人的股动脉舒张功能，并增加循环中的ET-1。有必要基于这些证据进行长期观察，以更好地了解长时间坐着可能带来的与血管相关的长期后果。这是第一项研究长时间坐着对心血管疾病风险增加的成年人动脉功能影响的研究。我们已经表明，与定期中断坐姿相比，5小时的长时间坐着会损害超重/肥胖成年人的股动脉舒张功能，并增加循环中的内皮素-1。现在有必要基于这些证据进行长期观察，以更好地了解长时间坐着可能带来的与血管相关的长期后果。
