Association between reduced bronchodilatory effect of deep inspiration and loss of alveolar attachments

Scichilone, Nicola; Bruno, Andreina; Marchese, Roberto; Vignola, Antonio M.; Togias, Alkis; Bellia, Vincenzo

doi:10.1186/1465-9921-6-55

Cited by 23 publications

(22 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Image acquisition parameters by scanner are described in e- Table 1. radial traction of the surrounding parenchyma. Scichilone et al 4 since have substantiated this observation in lung tissue from subjects with COPD. They showed that the loss of alveolar attachments to airway walls is associated with a decrease in bronchodilatory response to deep inspiration.…”

Section: Ct Scan Examinationmentioning

confidence: 76%

Association Between Airway Caliber Changes With Lung Inflation and Emphysema Assessed by Volumetric CT Scan in Subjects With COPD

Díaz

Come

Ross

et al. 2012

Chest

View full text Add to dashboard Cite

A defi ning characteristic of COPD is expiratory airfl ow limitation due to intrinsic remodeling of the small airways and their dynamic collapse during forced exhalation. 1 In a normal lung, infl ation results in a predictable increase in airway caliber because of the interdependence of parenchyma and airways (the relative change in airway diameter is linearly related with the cube root of lung volume). 2 Emphysema alters this relationship by disrupting airway-parenchymal interdependence. Early work in small animals demonstrated that methacholine-induced bronchoconstriction was increased in elastase models of emphysema, 3 suggesting that the bronchoconstrictive effect of airway smooth muscle activation is opposed by the Background: An increase in airway caliber (airway distensibility) with lung infl ation is attenuated in COPD. Furthermore, some subjects have a decrease in airway caliber with lung infl ation. We aimed to test the hypothesis that airway caliber increases are lower in subjects with emphysemapredominant (EP) compared with airway-predominant (AP) CT scan subtypes. Additionally, we compared clinical and CT scan features of subjects with (airway constrictors) and without a decrease in airway caliber. Methods: Based on GOLD (Global Initiative for Chronic Obstructive Lung Disease) stages and CT scan subtypes, we created a control group (n 5 46) and the following matched COPD groups (n 5 23 each): GOLD-2-AP, GOLD-2-EP, GOLD-4-AP, and GOLD-4-EP. From the CT scans of all 138 subjects, we measured emphysema, lung volumes, and caliber changes in the third and fourth airway generations of two bronchi. We expressed airway distensibility (ratio of airway lumen diameter change to lung volume change from end tidal breathing to full inspiration) as a global or lobar measure based on normalization by whole-lung or lobar volume changes. Results: Global distensibility in the third and fourth airway generations was signifi cantly lower in the GOLD-2-EP and GOLD-4-EP groups than in control subjects. In GOLD-2 subjects, lobar distensibility of the right-upper-lobe fourth airway generation was signifi cantly lower in those with EP than in those with AP. In multivariate analysis, emphysema was an independent determinant of global and lobar airway distensibility. Compared with nonconstrictors, airway constrictors experienced more dyspnea, were more hyperinfl ated, and had a higher percentage of emphysema. Conclusions: Distensibility of large-to medium-sized airways is reduced in subjects with an EP CT scan subtype. Emphysema seems to alter airway-parenchyma interdependence.

show abstract

Section: Ct Scan Examinationmentioning

confidence: 76%

Association Between Airway Caliber Changes With Lung Inflation and Emphysema Assessed by Volumetric CT Scan in Subjects With COPD

Díaz

Come

Ross

et al. 2012

Chest

View full text Add to dashboard Cite

show abstract

“…15,16 There may be several reasons for this observation, including mural fi brosis, which prevents dilation, and the disruption of the airway-parenchymal interdependence in emphysematous lungs, 15 which may reduce radial traction on the airway. 17 In either case, an incompletely expanded airway may appear to have an elevated WA% on CT scan that could be falsely attributed to a greater burden of airway disease. Because the increase in WA% beyond the segmental airways is the basis of the increased correlation between lung function and airway disease, it is important to uncover whether this measure is related to emphysema.…”

Section: Discussionmentioning

confidence: 99%

“…A prior study in subjects with COPD found that destructive changes in alveolar walls reduce the number of alveolar attachments on airways, leading to parenchymal-airway uncoupling, which in turn diminishes airway dilation. 17 This process may be less prominent in airways capable of being visualized on CT scan. Despite these limitations, we speculate that CT scan measures of WA% may not exclusively represent an airway remodeling process.…”

Section: Acknowledgmentsmentioning

confidence: 99%

Effect of Emphysema on CT Scan Measures of Airway Dimensions in Smokers

Díaz

Han

Come

et al. 2013

Chest

View full text Add to dashboard Cite

Background: In CT scans of smokers with COPD, the subsegmental airway wall area percent (WA%) is greater and more strongly correlated with FEV 1 % predicted than WA% obtained in the segmental airways. Because emphysema is linked to loss of airway tethering and may limit airway expansion, increases in WA% may be related to emphysema and not solely to remodeling. We aimed to fi rst determine whether the stronger association of subsegmental vs segmental WA% with FEV 1 % predicted is mitigated by emphysema and, second, to assess the relationships among emphysema, WA%, and total bronchial area (TBA). Methods: We analyzed CT scan segmental and subsegmental WA% (WA% 5 100 3 wall area/TBA) of six bronchial paths and corresponding lobar emphysema, lung function, and clinical data in 983 smokers with COPD. Results: Compared with segmental WA%, the subsegmental WA% had a greater effect on FEV 1 % predicted ( 2 0.8% to 2 1.7% vs 2 1.9% to 2 2.6% per 1-unit increase in WA%, respectively; P , .05 for most bronchial paths). After adjusting for emphysema, the association between subsegmental WA% and FEV 1 % predicted was weakened in two bronchial paths. Increases in WA% between bronchial segments correlated directly with emphysema in all bronchial paths ( P , .05). In multivariate regression models, emphysema was directly related to subsegmental WA% in most bronchial paths and inversely related to subsegmental TBA in all bronchial paths. Conclusion: The greater effect of subsegmental WA% on airfl ow obstruction is mitigated by emphysema. Part of the emphysema effect might be due to loss of airway tethering, leading to a reduction in TBA and an increase in WA%.

show abstract

“…Loss of alveolar attachments has been related to decreased airflow [147], to the reduced bronchodilating effect of a deep inspiration [148,149] and to abnormal distribution of ventilation [150].…”

Section: Airway Wall Collapsementioning

confidence: 99%

Clinical relevance of airway remodelling in airway diseases

James¹,

Wenzel²

2007

European Respiratory Journal

299

214

View full text Add to dashboard Cite

Asthma and chronic obstructive pulmonary disease (COPD) are characterised by airflow obstruction, airway remodelling (measurable structural change) and inflammation. The present review will examine the relationship between airway remodelling in these two conditions with respect to symptoms, abnormal lung function, airway hyperresponsiveness and decline in lung function. The potential for remodelling to be a protective response will also be discussed.Asthma is associated with variable symptoms and changes in lung function and also fixed abnormalities of lung function and an increased rate of decline in lung function with age. There is a relative preservation of the relaxed airway lumen dimensions, prominent thickening of the smooth muscle layer and reduced airway distensibility. The severity of asthma is related to the degree of airway remodelling, which is most marked in cases of fatal asthma.In COPD, symptoms are persistent and predictable but also progressive and are related to fixed abnormalities of lung function. Remodelling is associated with narrowing of the airway lumen and an increased thickness of the airway wall, although not usually to the extent seen in asthma. COPD is most often due to smoking where there is also remodelling of the parenchyma that may contribute to symptoms.

show abstract

Association between reduced bronchodilatory effect of deep inspiration and loss of alveolar attachments

Abstract: Background: We have previously shown that the bronchodilatory effect of deep inspiration is attenuated in individuals with COPD. This study was designed to investigate whether the impairment in this effect is associated with loss of alveolar attachments.

Cited by 23 publications

References 21 publications

Association Between Airway Caliber Changes With Lung Inflation and Emphysema Assessed by Volumetric CT Scan in Subjects With COPD

Association Between Airway Caliber Changes With Lung Inflation and Emphysema Assessed by Volumetric CT Scan in Subjects With COPD

Effect of Emphysema on CT Scan Measures of Airway Dimensions in Smokers

Clinical relevance of airway remodelling in airway diseases

Contact Info

Product

Resources

About