Bronchial Responsiveness Testing Research Articles

Evaluation of the persistence of functional and biological respiratory health effects in clean-up workers 6 years after the Prestige oil spill

Fishermen who had participated in clean-up activities of the Prestige oil spill showed increased bronchial responsiveness and higher levels of respiratory biomarkers 2years later. We aimed to evaluate the persistence of these functional and biological respiratory health effects 6years after clean-up work. In 2008/2009 a follow-up study was done in 230 never-smoking fishermen who had been exposed to clean-up work in 2002/2003 and 87 non-exposed fishermen. Lung function and bronchial responsiveness testing and the determination of respiratory biomarkers in exhaled breath condensate were done identically as in the baseline survey in 2004/2005. Associations between participation in clean-up work and respiratory health parameters were assessed using linear and logistic regression analyses adjusting for sex and age. Information from 158 exposed (69%) and 57 non-exposed (66%) fishermen was obtained. Loss to follow-up in the non-exposed was characterised by less respiratory symptoms at baseline. During the 4-year follow-up period lung function, bronchial hyperresponsiveness and the levels of respiratory biomarkers of oxidative stress and growth factors had deteriorated notably more among non-exposed than among exposed. At follow-up, respiratory health indices were similar or better in clean-up workers than in non-exposed. No clear differences between highly exposed and moderately exposed clean-up workers were found. In conclusion, we could not detect long-term respiratory health effects in clean-up workers 6years after the Prestige oil spill. Methodological issues that need to be considered in this type of studies include the choice of a non-exposed control group and limitation of follow-up to subgroups such as never smokers.

Respiratory health in firefighters

ObjectivesThe aim of the present study was to determine associations between respiratory health and exposure to smoke of fires.MethodsThe studies comprised 3 subsequent stages. First, all active firefighters of the...

Assessing clinical and spirometric control and the intensity of the inflammatory process in asthma

To review the role of clinical assessment, quality of life assessment, spirometry, bronchial responsiveness test and inflammatory markers for asthma assessment. Search run on MEDLINE and LILACS. Clinical assessment aids with assessing asthma control and is widely recommended. However, patients may have airway inflammation and obstruction despite normal clinical findings. Spirometry quantifies the degree of airway obstruction and helps with diagnosis, while the bronchial responsiveness test may be indicated for when asthma is suspected but spirometry is normal. The results of assaying the inflammatory markers in exhaled breath condensate, induced sputum, bronchoalveolar lavage and bronchial biopsy specimens are abnormal in asthma patients, but these are complex techniques almost always restricted to research. Fractional exhaled nitric oxide (FeNO) is elevated in patients with asthma, is reproducible and noninvasive and reduces with treatment. Studies have investigated using FeNO to help with adjusting inhaled corticoid dosages, but the benefits are not clear. A range of different methods are needed to accurately assess disease control, all with their advantages and limitations. Clinical and functional assessment is useful for diagnosing asthma, but is of limited use for precisely evaluating the intensity of the inflammatory process in the airways. More randomized and controlled studies with adequate statistical power should be carried out to investigate the true utility of noninvasive inflammatory markers, especially FeNO, for asthma management.

Analyses of associations between three positionally cloned asthma candidate genes and asthma or asthma-related phenotypes in a Chinese population

BackgroundSix asthma candidate genes, ADAM33, NPSR1, PHF11, DPP10, HLA-G, and CYFIP2, located at different chromosome regions have been positionally cloned following the reported linkage studies. For ADAM33, NPSR1, and CYFIP2, the associations with asthma or asthma-related phenotypes have been studied in East Asian populations such as Chinese and Japanese. However, for PHF11, DPP10, and HLA-G, none of the association studies have been conducted in Asian populations. Therefore, the aim of the present study is to test the associations between these three positionally cloned genes and asthma or asthma-related phenotypes in a Chinese population.MethodsTwo, five, and two single nucleotide polymorphisms (SNPs) in the identified top regions of PHF11, DPP10, and HLA-G, respectively, were genotyped in 1183 independent samples. The study samples were selected based on asthma affectation status and extreme values in at least one of the following three asthma-related phenotypes: total serum immunoglobulin E levels, bronchial responsiveness test, and skin prick test. Both single SNP and haplotype analyses were performed.ResultsWe found that DPP10 was significantly associated with bronchial hyperresponsiveness (BHR) and BHR asthma after the adjustment for multiple testing; while the associations of PHF11 with positive skin reactions to antigens and the associations of HLA-G with BHR asthma were only nominally significant.ConclusionOur study is the first one to provide additional evidence that supports the roles of DPP10 in influencing asthma or BHR in a Chinese population.

Bronchial responsiveness in bakery workers: relation to airway symptoms, IgE sensitization, nasal indices of inflammation, flour dust exposure and smoking

Bronchial hyperresponsiveness (BHR) is common in bakery workers. The relation between bronchial responsiveness measured with a tidal breathing method and smoking, airway symptoms, IgE-sensitization, nasal indices of inflammation and flour dust exposure have been studied with bronchial responsiveness expressed as a continuous outcome. Bakery workers (n = 197) were subjected to interviews, questionnaires, allergy tests, workplace dust measurements and bronchial metacholine provocation. Eosinophil cationic protein (ECP) and alpha(2)-macroglobulin were measured in nasal lavage. Bronchial responsiveness was expressed as slope(conc), a measurement based on regressing the per cent reduction in FEV(1) at each provocation step. BHR expressed as slope(conc) was associated with smoking (P = 0.009), asthma symptoms at work (P = 0.001), and occupational IgE sensitization (P = 0.048). After adjusting for baseline lung function the association between BHR and IgE sensitization was no longer present. We demonstrated an association between nasal ECP and BHR (slope(conc) < 3: P = 0.012), but not to alpha(2)-macroglobulin in nasal lavage. No association was seen between BHR and current exposure level of flour dust, number of working years in a bakery or a history of dough-making. BHR is related to baseline lung function, work-related asthma symptoms, smoking and nasal eosinophil activity, but not to occupational IgE sensitization and current flour dust exposure when measured with metacholine provocation. The slope(conc) expression seems to be a useful continuous outcome in bronchial responsiveness testing.

The video questionnaire: one approach to the identification of the asthmatic phenotype.

The video questionnaire: one approach to the identification of the asthmatic phenotype.

Prevalence of asthma-related symptoms and bronchial responsiveness to exercise in children aged 13-14 yrs in Barcelona, Spain.

It is not clear whether asymptomatic bronchial responsiveness is a risk factor for development of asthma. A cross-sectional study was conducted to determine the prevalence of asthma among schoolchildren from Barcelona (Spain). The association between respiratory symptoms and bronchial responsiveness to exercise was examined. For this study 3,033 schoolchildren aged 13-14 yrs were studied from the general population. Participants answered a respiratory questionnaire and a self-reporting video-questionnaire. A total of 2,842 children underwent bronchial responsiveness testing by exercise challenge. The study was part of the International Study of Asthma and Allergies in Childhood (ISAAC) project. The prevalence of "current asthma" (recent wheezing and bronchial responsiveness to exercise) was 4% and the prevalence of "wheezing only" 10%. A fall in peak expiratory flow rate (PEFR) > or = 15% after exercise testing was found in 324 (11%) children, 29 (9%) of whom presented clinical symptoms of asthma. Bronchial responsiveness to exercise was significantly associated with all items of the asthma questionnaire. The prevalence of asthma-related symptoms in this inner-city area was lower than frequently reported rates in other countries, although the prevalence of exercise-induced bronchoconstriction was relatively high, and threefold greater than in a geographical area in the vicinity of Barcelona. These findings are consistent with the current view that asthma-related symptoms and bronchial responsiveness to exercise have different meanings in a community survey, and that local environmental factors could influence the prevalence of bronchial responsiveness.

Serum house dust mite antibodies: predictor of increased bronchial responsiveness in adults of a community.

The purpose of this study was to determine whether the presence of serum specific immunoglobulin E (IgE) antibodies was associated with increased bronchial responsiveness in adults. We studied cross-sectionally a random community sample of 18-73 year old adults, of whom 83% (n = 489) performed bronchial responsiveness testing as well as serum measurements of five specific IgE antibodies. In the crude data, 39% of those with house dust mite antibodies (n = 18) had a bronchial responsiveness < or = 32 g.L-1 methacholine compared with 19% in subjects without any of the five specific IgE antibodies (n = 453). The corresponding percentages for subjects with timothy antibodies (n = 16) was 25%, birch antibodies (n = 13) 23%, cat antibodies (n = 10) 40% and mould antibodies (n = 2) 50%. When assessing the multivariate relationship between the presence of one specific IgE antibody and degree of bronchial responsiveness we used a semi-proportional hazards model with the response as a 20% fall in forced expiratory volume in one second (FEV1) from pretest value. Covariates included in the model were: gender, age, pretest FEV1, smoking habits, pack-years, season and other specific IgE antibodies than that examined. The presence of house dust mite antibodies was a significant predictor (p < 0.01) of increased bronchial responsiveness in never- and ex-smokers. Indoor allergic sensitization (house dust mite, cat and mould) was a significant predictor of increased bronchial responsiveness, while outdoor allergic sensitization (timothy and birch) was not. Excluding subjects with obstructive lung disease (n = 39) or including the covariate log total serum IgE as a potential confounder yielded the same result. Thus, in this community, indoor allergic sensitization rather than allergic sensitization per se was related to increased bronchial responsiveness after adjusting for other relevant covariates.