Six-minute walking-induced systemic inflammation and oxidative stress in muscle-wasted COPD patients.

Contains fulltext : 52321.pdf (publisher's version ) (Closed access)BACKGROUND: Systemic inflammation and oxidative stress are potential mechanisms for muscle wasting in COPD patients. Six-minute walking testing (6MWT) has been suggested as simple and valid exercise test in COPD that is well tolerated, and reflective of activities of daily living. The present study investigated physiologic and systemic immunologic responses to a 6MWT in muscle-wasted patients with COPD and compared them with maximal cardiopulmonary exercise testing (CPET). METHODS: Ten patients with muscle-wasted COPD were included (fat-free mass index [FFMI]: men, < 16 kg/m2; women, < 15 kg/m2). 6MWT and CPET were performed in random order. The physiologic response was followed by a mobile oxycon. Arterial blood was obtained at rest and after exercise to measure blood gases and markers of systemic inflammation and oxidative stress. RESULTS: In these patients (FEV1 55 +/- 4% of predicted [mean +/- SE]), the 6MWT was a submaximal, albeit intense, exercise as reflected by oxygen uptake (VO2), minute ventilation, heart rate, and lactate values. Leukocytosis was less intense after 6MWT compared to CPET. Contrary, the increase in interleukin-6, free radical release by neutrophils, oxidation of proteins and lipids, and the reduction in antioxidant capacity were similar after both exercises. FFMI was inversely related to 6MWT-induced increases in protein and lipid peroxidation. CONCLUSIONS: This study shows that a 6MWT induces a systemic immunologic response in muscle-wasted patients with COPD, which is comparable to CPET-induced responses. The correlation between systemic oxidative stress and the degree of muscle wasting supports a possible causal relation between systemic inflammation, oxidative stress, and muscle wasting

Dynamic hyperinflation during daily activities: does COPD global initiative for chronic obstructive lung disease stage matter?

Contains fulltext : 88820.pdf (publisher's version ) (Closed access)BACKGROUND: One of the contributors to exercise limitation in COPD is dynamic hyperinflation. Although dynamic hyperinflation appears to occur during several exercise protocols in COPD and seems to increase with increasing disease severity, it is unknown whether dynamic hyperinflation occurs at different severity stages according to the Global initiative for chronic Obstructive Lung Disease (GOLD) in daily life. The present study, therefore, aimed to compare dynamic hyperinflation between COPD GOLD stages II-IV during daily activities. METHODS: Thirty-two clinically stable patients with COPD GOLD II (n = 10), III (n = 12), and IV (n = 10) participated in this study. Respiratory physiology during a daily activity was measured at patients' homes with Oxycon Mobile. Inspiratory capacity maneuvers were performed at rest, at 2-min intervals during the activity, and at the end of the activity. Change in inspiratory capacity is commonly used to reflect change in end-expiratory lung volume (DeltaEELV) and, therefore, dynamic hyperinflation. The combination of static and dynamic hyperinflation was reflected by inspiratory reserve volume (IRV) during the activity. RESULTS: Overall, increase in EELV occurred in GOLD II-IV without significant difference between the groups. There was a tendency for a smaller DeltaEELV in GOLD IV. DeltaEELV was inversely related to static hyperinflation. IRV during the daily activity was related to the level of airflow obstruction. CONCLUSIONS: Dynamic hyperinflation occurs independent of GOLD stage during real-life daily activities. The combination of static and dynamic hyperinflation, however, increases with increasing airflow obstruction.1 mei 201

Resting and ADL-induced dynamic hyperinflation explain physical inactivity in COPD better than FEV1

Item does not contain fulltextBACKGROUND: Physical activity and health status deteriorate early in the course of chronic obstructive pulmonary disease (COPD). This can only partially be explained by the degree of airflow limitation. Changes in (resting and dynamic) lung volumes are known to be associated with functional impairments and thus might influence physical activity level. The aim of the present cross-sectional study was to explore the contribution of dynamic hyperinflation during daily life activities (ADL) in the decline in physical activity. METHODS: Airflow limitation and inspiratory capacity at rest to total lung capacity ratio (IC/TLC) as a measure of resting hyperinflation were measured in 59 patients with COPD (GOLD I-IV). Mean daily physical activity was assessed with a tri-axial accelerometer. Measurements of dynamic hyperinflation during ADL (DeltaIC and inspiratory reserve volume at end ADL) were performed at patients' home using a portable breath-by-breath system. RESULTS: Multiple regression analysis showed that resting as well as ADL-induced dynamic hyperinflation independently contributed to decreased daily physical activity, together explaining 45.8% of the variance in physical activity. In contrast to hyperinflation, the severity of airflow limitation (FEV1) appeared to have no unique part in explaining how physically (in-) active patients were. CONCLUSIONS: The presence of resting hyperinflation and occurrence of dynamic hyperinflation during ADL contribute to reduced physical activity levels in patients with COPD, independently of the degree of airflow limitation

Systemic inflammatory response to exhaustive exercise in patients with chronic obstructive pulmonary disease.

Contains fulltext : 48447.pdf (publisher's version ) (Closed access)Systemic inflammation may be present in patients with chronic obstructive pulmonary disease (COPD). Exercise is known to elicit an inflammatory response. We hypothesized that the systemic inflammatory response to exercise might be exaggerated in COPD patients compared to healthy subjects. Sixteen COPD patients and 11 healthy subjects performed a maximal incremental bicycle test. Before and at maximal exercise arterial blood samples were taken to determine circulating catecholamines, (subsets of) leukocytes, acute phase proteins, creatine kinase and myoglobin. At rest, increased levels of norepinephrine and systemic inflammation were present in COPD. The response of catecholamines to exercise was lower in COPD patients (P<0.01), which in part was due to the lower maximal exercise capacity of these patients (P<0.01). Exercise-induced leukocytosis showed similar responses in both groups, but occurred at higher levels in COPD. Although patients had increased levels of CRP at rest (P<0.001), exercise did not affect acute phase proteins. No systemic signs of muscle damage were found. The present study shows that COPD patients are exposed to systemic inflammation that is intensified by exhaustive exercise. The inflammatory response in COPD is not exaggerated compared to healthy subjects but occurs at a higher level and is observed at lower external workload