Chronic obstructive pulmonary disease (COPD) is associated with increased cardiovascular mortality. Endothelial dysfunction may underpin this association. This cross-sectional study aimed to determine the impact of airflow obstruction, systemic inflammation, oxidative stress, sympathetic activation, hypoxaemia and physical activity on endothelial function in COPD.In stable COPD patients, assessments of endothelial function by flow-mediated dilatation (FMD), cardiovascular risk (Pocock score), airflow obstruction (forced expiratory volume in 1 s (FEV1)), systemic inflammation (high-sensitivity C-reactive protein and interleukin-6), oxidative stress (malondialdehyde), sympathetic activation (baroreflex sensitivity), hypoxaemia (arterial oxygen tension), hypercapnia (arterial carbon dioxide tension (PaCO 2 )), physical activity (steps per day) and exercise capacity (6-min walking distance) were performed. Associations between FMD and potential determinants were assessed in univariate and multivariate analyses.106 patients (Global Initiative for Chronic Obstructive Lung Disease stage I/II 35%, stage III 25% and stage IV 40%) were included. In multivariate analysis FEV1 was positively associated with FMD, independent of other significant FMD determinants from univariate analysis (sex, smoking, combined inhaled long-acting b-adrenergic and steroid medication, heart rate, baroreflex sensitivity and PaCO 2 ) and adjusted for potential confounders (cardiovascular risk and age). In addition, the FMD and FEV1 association was modified by physical activity.The findings of this study demonstrate that the severity of airflow obstruction is a significant determinant of endothelial function in patients with COPD. A high level of physical activity seems to have a favourable effect on this association. @ERSpublications In COPD, the association between airflow obstruction and impaired endothelial function is modified by physical activity

Nasal prong pressure monitoring (PNOSE) is utilized to assess ventilation during sleep. However, it has not been rigorously validated against the gold standard of face-mask pneumotachography (VFM). Therefore, we compared PNOSE with VFM in 20 patients with suspected sleep apnea during nocturnal polysomnography, and analyzed factors affecting accuracy of PNOSE-derived variables. Patients rated their nasal obstruction on a visual analog scale. Mean +/- SE apnea/hypopnea index (AHI) by VFM was 24.0 +/- 5.1 h(-1). The bias (mean difference) and limits of agreement (+/- 2 SD) of AHI derived from PNOSE, and square root-transformed PNOSE, a measure proposed as a surrogate of airflow, were +3.9 (+/- 4.6), and -0.9 (+/- 9.0) h(-1). Subjective scores of nasal obstruction before polysomnographies did not herald inaccuracy of AHI from PNOSE. Square root-transformed PNOSE closely tracked pneumotachographic airflow over 10 breaths (r(2) among signals 0.88 to 0.96) but the relationship among these signals was highly variable if comparisons were extended over an entire night. Compared with face-mask pneumotachography, nasal pressure monitoring provides accurate AHI for clinical purposes even in patients perceiving nasal obstruction. Square-root transformation provides near linear nasal pressure/airflow relationships over a short time but is not essential for estimation of AHI.

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Lung perfusion scintigraphy is employed to evaluate patients with severe emphysema who are candidates for lung volume reduction surgery (LVRS). Our purpose was to investigate the role of scintigraphy in relation to chest computed tomography (CT) and lung function in this setting. Six observers blinded to clinical data retrospectively scored preoperative scintigrams of 70 patients undergoing bilateral video-assisted LVRS according to the distribution of lung perfusion as homogeneous, intermediately heterogeneous, or markedly heterogeneous. Heterogeneity of emphysema distribution was also assessed by chest CT. Dyspnea and pulmonary function were measured preoperatively and 3 mo postoperatively. In 42 patients with markedly heterogeneous, in 18 with intermediately heterogeneous, and in 10 with homogeneous perfusion, mean (+/- SE) FEV1 increased by 57 +/- 8% (p < 0.0001), 38 +/- 9% (p < 0.001), and 23 +/- 9% (p = NS) (p = NS for intergroup comparisons). In a multiple regression analysis, functional improvement after LVRS was more closely correlated with preoperative hyperinflation and the degree of emphysema heterogeneity estimated by chest CT than with the degree of perfusion heterogeneity assessed by scintigraphy. In 16 of 22 patients with homogeneous emphysema distribution in the chest CT scintigraphy revealed intermediately or markedly heterogeneous perfusion. We conclude that lung perfusion scintigraphy has a limited role in prediction of outcome, but it may help to identify target areas for resection in LVRS candidates with homogeneous CT morphology.