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Background: Heterogeneous airway narrowing and closure are characteristics of asthma. However, they have never been quantified by direct measurements of parallel sister airways obtained from image data, and the anatomical basis of these processes remains unknown.Methods: Seven normal and nine asthmatic subjects underwent high-resolution CT, before and after methacholine challenge. Mean lumen areas of the entire airways were measured in 28 and 24 parallel sister airway pairs (a pair of airways arising from the same bifurcation) respectively (range 1.0-8.7 mm diameter). Heterogeneous narrowing was defined as the median difference in percentage narrowing between parallel sister airways. Forced oscillatory respiratory resistance (Rrs) and spirometry were measured before and after methacholine challenge conducted while supine.Results: The airways of asthmatics were smaller at baseline, and following bronchoconstriction there were similar decreases in FEV1, increases in Rrs and mean narrowing of airways for asthmatic and non-asthmatic groups. Non-asthmatics required higher doses of methacholine than asthmatics to achieve the same changes. However, parallel heterogeneity (median (IQR) 33% (27-53%) vs 11% (9-18%), p<0.001) and airway closure (24.1% and 7.7%, p=0.001, χ(2)) were greater in asthmatics versus non-asthmatics.Conclusion: We found clear evidence of differences in airway behaviour in the asthmatic group. Asthmatic airways were narrower at baseline and responded to inhaled methacholine by more heterogeneous narrowing of parallel sister airways and greater airway closure. [ABSTRACT FROM AUTHOR]

Paediatric asthma hospitalisation trends in Finland and Sweden over the past 10 years are unclear. We investigated the incidence of paediatric asthma hospitalisations in both countries from 2005 to 2014, using Finland's National Hospital Discharge Register and Sweden's National Patient Register which cover all hospitalisations in the respective countries. During the study period, the incidence of paediatric asthma hospitalisations decreased by 51% in Finland, but remained stable in Sweden. In both countries, asthma hospitalisations decreased over time among children aged 0-4 years, with unclear trends for older ages. The reasons for these intercountry differences are unclear, thus warranting future research. [ABSTRACT FROM AUTHOR]

The article discusses a scientific study of lung function in individuals from infancy to late adolescence with a focus on what factors are associated with changes in function. Topics include the impact that gender, asthma, and maternal asthma have on lung function, the correlation between infant onset atopy, maternal smoking, and low lung function, and expiratory flow limitation in lung function.

Background Hyperpolarised ³He MRI provides a way to visualise regional pulmonary functional abnormalities that in asthma are thought to be related to airway morphological abnormalities. However, the exact aetiology of ventilation defects in asthma is not well understood. Objective To better understand the determinants of ventilation defects in asthma, we evaluated wellestablished clinical as well as ³He MRI and X-ray CT airway measurements in healthy subjects and subjects with asthma. Methods Thirty-four subjects (n=26 subjects with asthma, n=8 healthy volunteers) underwent MRI, spirometry, plethysmography, fraction of exhaled nitric oxide analysis, methacholine challenge and CT for a region-of-interest proximal to ventilation defects. For subjects who consented to CT (n=18 subjects with asthma, n=5 healthy volunteers), we evaluated 3rd to 5th generation airway wall area and wall thickness per cent and lumen area. Results Seventeen subjects with asthma (17/26=65%) had visually obvious evidence of ³He ventilation defects prior to bronchoprovocation and nine subjects with asthma had no ventilation defects prior to bronchoprovocation (9/26=35%). Subjects with asthma with defects were older (p=0.01) with worse forced expiratory volume in 1 s (FEV1)/forced vital capacity (p=0.0003), airways resistance (p=0.004), fraction of exhaled nitric oxide (p=0.03), greater bronchoprovocation concentration of methacholine that reduced FEV1 by 20% ( p=0.008) and wall thickness per cent (p=0.02) compared with subjects with asthma without defects. There was a moderate correlation for wall area per cent with ventilation defect per cent (r=0.43, p=0.04). Conclusions Subjects with asthma with ³He ventilation defects were older with significantly worse airway hyperresponsiveness, inflammation and airway remodelling but similar FEV1 as subjects with asthma without defects; hyperpolarised ³He ventilation abnormalities were spatially and quantitatively related to abnormally remodelled airways. [ABSTRACT FROM AUTHOR]

In the majority of cases, asthma and chronic obstructive pulmonary disease (COPD) are two clearly distinct disease entities. However, in some patients there may be significant overlap between the two conditions. This constitutes an important area of concern because these patients are generally excluded from randomised controlled trials (mostly because of smoking history in the case of asthma or because of significant bronchodilator reversibility in the case of COPD). As a result, their pathobiology, prognosis and response to therapy are largely unknown. This may lead to suboptimal management and can limit the development of more personalised therapeutic options. Emerging genetic and molecular information coupled with new bioinformatics capabilities provide novel information that can pave the way towards a new taxonomy of airway diseases. In this paper we question the current value of the terms 'asthma' and 'COPD' as still useful diagnostic labels; discuss the scientific and clinical progress made over the past few years towards unravelling the complexity of airway diseases, from the definition of clinical phenotypes and endotypes to a better understanding of cellular and molecular networks as key pathogenic elements of human diseases (so-called systems medicine); and summarise a number of ongoing studies with the potential to move the field towards a new taxonomy of airways diseases and, hopefully, a more personalised approach to medicine, in which the focus will shift from the current goal of treating diseases as best as possible to the so-called P4 medicine, a new type of medicine that is predictive, preventive, personalised and participatory. [ABSTRACT FROM AUTHOR]

BACKGROUND: Epidemiological studies suggest that dietary intake of vitamins A, C and E may be associated with the occurrence of asthma. A systematic review and meta-analysis was conducted in accordance with MOOSE guidelines to determine whether vitamins A, C and E, measured as dietary intakes or serum levels, are associated with asthma. METHODS: MEDLINE, EMBASE, CINAHL, CAB abstracts and AMED (up to November 2007), conference proceedings and bibliographies of papers were searched to identify studies of asthma, wheeze or airway responsiveness in relation to intakes and serum concentrations of vitamins A, C and E. Pooled odds ratios (OR) or mean differences (MD) with 95% confidence intervals (CI) were estimated using random effects models. RESULTS: A total of 40 studies were included. Dietary vitamin A intake was significantly lower in people with asthma than in those without asthma (MD –182 µg/day, 95% CI –288 to –75; 3 studies) and in people with severe asthma than in those with mild asthma (MD –344 µg/day; 2 studies). Lower quantile dietary intakes (OR 1.12, 95% CI 1.04 to 1.21; 9 studies) and serum levels of vitamin C were also associated with an increased odds of asthma. Vitamin E intake was generally unrelated to asthma status but was significantly lower in severe asthma than in mild asthma (MD –1.20 µg/day, 95% CI –2.3 to –0.1; 2 studies). CONCLUSIONS: Relatively low dietary intakes of vitamins A and C are associated with statistically significant increased odds of asthma and wheeze. Vitamin E intake does not appear to be related to asthma status. [ABSTRACT FROM AUTHOR]