PDF(Pubmed)
Abstract：
BACKGROUND: Cardiovascular comorbidities are increasingly being recognised in early stages of chronic obstructive pulmonary disease (COPD) yet complete cardiorespiratory functional assessments of individuals with mild COPD or presenting with COPD risk factors are lacking. This paper reports on the effectiveness of the cardiocirculatory-limb muscles oxygen delivery and utilisation axis in smokers exhibiting no, or mild to moderate degrees of airflow obstruction using standardised cardiopulmonary exercise testing (CPET).
METHODS: Post-bronchodilator spirometry was used to classify participants as \'ever smokers without\' (n=88), with \'mild\' (n=63) or \'mild-moderate\' COPD (n=56). All underwent CPET with continuous concurrent monitoring of oxygen uptake (V\'O2) and of bioimpedance cardiac output (Qc) enabling computation of arteriovenous differences (a-vO2). Mean values of Qc and a-vO2 were mapped across set ranges of V\'O2 and Qc isolines to allow for meaningful group comparisons, at same metabolic and circulatory requirements.
RESULTS: Peak exercise capacity was significantly reduced in the \'mild-moderate COPD\' as compared with the two other groups who showed similar pulmonary function and exercise capacity. Self-reported cardiovascular and skeletal muscle comorbidities were not different between groups, yet disease impact and exercise intolerance scores were three times higher in the \'mild-moderate COPD\' compared with the other groups. Mapping of exercise Qc and a-vO2 also showed a leftward shift of values in this group, indicative of a deficit in peripheral O2 extraction even for submaximal exercise demands. Concurrent with lung hyperinflation, a distinctive blunting of exercise stroke volume expansion was also observed in this group.
CONCLUSIONS: Contrary to the traditional view that cardiovascular complications were the hallmark of advanced disease, this study of early COPD spectrum showed a reduced exercise O2 delivery and utilisation in individuals meeting spirometry criteria for stage II COPD. These findings reinforce the preventive clinical management approach to preserve peripheral muscle circulatory and oxidative capacities.
METHODS: Post-bronchodilator spirometry was used to classify participants as \'ever smokers without\' (n=88), with \'mild\' (n=63) or \'mild-moderate\' COPD (n=56). All underwent CPET with continuous concurrent monitoring of oxygen uptake (V\'O2) and of bioimpedance cardiac output (Qc) enabling computation of arteriovenous differences (a-vO2). Mean values of Qc and a-vO2 were mapped across set ranges of V\'O2 and Qc isolines to allow for meaningful group comparisons, at same metabolic and circulatory requirements.
RESULTS: Peak exercise capacity was significantly reduced in the \'mild-moderate COPD\' as compared with the two other groups who showed similar pulmonary function and exercise capacity. Self-reported cardiovascular and skeletal muscle comorbidities were not different between groups, yet disease impact and exercise intolerance scores were three times higher in the \'mild-moderate COPD\' compared with the other groups. Mapping of exercise Qc and a-vO2 also showed a leftward shift of values in this group, indicative of a deficit in peripheral O2 extraction even for submaximal exercise demands. Concurrent with lung hyperinflation, a distinctive blunting of exercise stroke volume expansion was also observed in this group.
CONCLUSIONS: Contrary to the traditional view that cardiovascular complications were the hallmark of advanced disease, this study of early COPD spectrum showed a reduced exercise O2 delivery and utilisation in individuals meeting spirometry criteria for stage II COPD. These findings reinforce the preventive clinical management approach to preserve peripheral muscle circulatory and oxidative capacities.
摘要：
背景：在慢性阻塞性肺疾病（COPD）的早期阶段，心血管合并症越来越多地被认识到，但缺乏对轻度COPD或有COPD危险因素的个体进行完整的心肺功能评估。本文报道了在吸烟者中心脏循环肢体肌肉氧气输送和利用轴的有效性，或使用标准化心肺运动测试（CPET）轻度至中度的气流阻塞。
方法：使用支气管扩张剂后肺活量测定法将参与者分类为“没有吸烟者”（n=88），患有“轻度”（n=63）或“轻度-中度”COPD（n=56）。所有患者均接受了CPET，同时连续监测氧摄取（V'O2）和生物阻抗心输出量（Qc），从而可以计算动静脉差异（a-vO2）。Qc和a-vO2的平均值在V\'O2和Qc等值线的设定范围内进行映射，以便进行有意义的组比较，在相同的代谢和循环要求。
结果：与表现出相似的肺功能和运动能力的其他两组相比，轻度-中度COPD的峰值运动能力明显降低。自我报告的心血管和骨骼肌合并症在组间没有差异，然而,与其他组相比,轻-中度COPD组的疾病影响和运动不耐受评分高出3倍.运动Qc和a-vO2的映射也显示该组中的值向左移动，即使对于亚最大的运动需求，也表明外周O2提取不足。伴随着肺过度膨胀，在该组中还观察到运动卒中体积扩张的明显钝化.
结论：与传统观点相反，传统观点认为心血管并发症是晚期疾病的标志，这项对早期COPD谱的研究显示,在符合II期COPD肺活量测定标准的个体中,运动O2输送和利用率降低.这些发现加强了预防性临床管理方法，以保持外周肌肉的循环和氧化能力。
方法：使用支气管扩张剂后肺活量测定法将参与者分类为“没有吸烟者”（n=88），患有“轻度”（n=63）或“轻度-中度”COPD（n=56）。所有患者均接受了CPET，同时连续监测氧摄取（V'O2）和生物阻抗心输出量（Qc），从而可以计算动静脉差异（a-vO2）。Qc和a-vO2的平均值在V\'O2和Qc等值线的设定范围内进行映射，以便进行有意义的组比较，在相同的代谢和循环要求。
结果：与表现出相似的肺功能和运动能力的其他两组相比，轻度-中度COPD的峰值运动能力明显降低。自我报告的心血管和骨骼肌合并症在组间没有差异，然而,与其他组相比,轻-中度COPD组的疾病影响和运动不耐受评分高出3倍.运动Qc和a-vO2的映射也显示该组中的值向左移动，即使对于亚最大的运动需求，也表明外周O2提取不足。伴随着肺过度膨胀，在该组中还观察到运动卒中体积扩张的明显钝化.
结论：与传统观点相反，传统观点认为心血管并发症是晚期疾病的标志，这项对早期COPD谱的研究显示,在符合II期COPD肺活量测定标准的个体中,运动O2输送和利用率降低.这些发现加强了预防性临床管理方法，以保持外周肌肉的循环和氧化能力。
