1Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, CANADA; 2Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, CANADA; 3Cumming School of Medicine, University of Calgary, Calgary, Alberta, CANADA; 4Department of Medicine, University of Calgary, Calgary, Alberta, CANADA; 5Snyder Institute for Chronic Diseases, University of Calgary, Calgary, Alberta, CANADA; 6Department of Cardiac Sciences, University of Calgary, Calgary, Alberta, CANADA; 7Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, Alberta, CANADA; 8Department of Clinical Neuroscience, University of Calgary, Calgary, Alberta, CANADA; and 9Faculty of Kinesiology, University of Calgary, Calgary, Alberta, CANADA.
Med Sci Sports Exerc. 2016 Feb;48(2):200-9. doi: 10.1249/MSS.0000000000000766.
Chronic obstructive pulmonary disease (COPD) is associated with vascular dysfunction, possibly related to increased oxidative stress. Exercise hyperemia may similarly be impaired, which could have implications for exercise limitations in COPD. We tested if brachial blood flow (BBF) was reduced during handgrip exercise in COPD and if this response would be improved after vitamin C infusion.
Doppler ultrasound was used to measure brachial blood flow and vascular conductance (BBF and BVC, respectively) during mild, rhythmic handgrip exercise (EX) under conditions of sham-saline and vitamin C. Measures of flow-mediated dilation (FMD) and nitroglycerine-mediated dilation were used to assess endothelial-dependent and independent dilation, respectively. Biomarkers of antioxidants (vitamin C, superoxide dismutase [SOD], catalase), oxidative stress (malondialdehyde [MDA], advanced oxidation protein products [AOPP]), and nitric oxide metabolism (NOx) were measured in blood plasma.
Ten COPD patients with moderate COPD and 10 healthy age-matched controls participated. COPD patients had similar increases in BBF and BVC during EX, compared with controls. Vitamin C was not found to have an effect on blood flow parameters during exercise (P > 0.05). Markers of endothelial-dependent dilation (FMD) and nitroglycerin-mediated dilation were similar between groups at baseline; FMD improved similarly in both groups after vitamin C.
Moderate COPD patients have a preserved BBF response during handgrip exercise and do not exhibit endothelial dysfunction. Despite an increase in endothelial-dependent dilation after vitamin C, BBF remained unchanged, suggesting a limited impact of endothelial-derived NO in determining the blood flow response to handgrip exercise in older individuals. COPD patients of moderate severity, screened for cardiovascular disease, do not exhibit endothelial dysfunction and have similar exercise blood flow responses to healthy controls.
慢性阻塞性肺疾病（COPD）与血管功能障碍有关，可能与氧化应激增加有关。运动充血也可能受损，这可能对 COPD 患者的运动受限产生影响。我们检测了 COPD 患者在进行握力运动时肱动脉血流量（BBF）是否减少，以及维生素 C 输注后这种反应是否会改善。
采用多普勒超声测量轻度、有节奏的握力运动（EX）期间的肱动脉血流量和血管传导性（分别为 BBF 和 BVC），在假盐水和维生素 C 条件下。使用血流介导的扩张（FMD）和硝酸甘油介导的扩张来分别评估内皮依赖性和非依赖性扩张。测量血浆中的抗氧化剂（维生素 C、超氧化物歧化酶[SOD]、过氧化氢酶）、氧化应激（丙二醛[MDA]、高级氧化蛋白产物[AOPP]）和一氧化氮代谢（NOx）的生物标志物。
10 名患有中度 COPD 的 COPD 患者和 10 名年龄匹配的健康对照者参加了研究。与对照组相比，COPD 患者在 EX 期间的 BBF 和 BVC 增加相似。在运动期间，维生素 C 未发现对血流参数有影响（P > 0.05）。基线时，两组间内皮依赖性扩张标志物（FMD）和硝酸甘油介导的扩张相似；维生素 C 后两组的 FMD 均有相似改善。
中度 COPD 患者在握力运动期间具有保留的 BBF 反应，并且没有表现出内皮功能障碍。尽管维生素 C 后内皮依赖性扩张增加，但 BBF 保持不变，这表明内皮衍生的 NO 在确定老年人握力运动的血流反应方面的作用有限。筛选出心血管疾病的中度严重 COPD 患者没有表现出内皮功能障碍，并且与健康对照组具有相似的运动血流反应。
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