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- Bake, Björn, 1939, et al.
(författare)
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Exhaled Particles After a Standardized Breathing Maneuver
- 2017
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Ingår i: Journal of Aerosol Medicine and Pulmonary Drug Delivery. - : Mary Ann Liebert Inc. - 1941-2711 .- 1941-2703. ; 30:4, s. 267-273
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Tidskriftsartikel (refereegranskat)abstract
- Background: Particles in exhaled air (PEx) provide samples of respiratory tract lining fluid from small airways and offer a new opportunity to monitor pathological changes. The exhaled particles are produced by reopening of closed small airways and contain surfactant. The amount of PEx varies by orders of magnitude among subjects. A standardized breathing pattern reduces the variation, but it remains large and the reasons are unknown. The aim of the present study was to assess to what extent sex, age, body size, and spirometry results explain the interindividual variation of PEx among healthy middle-aged subjects. Methods: The PExA((R)) instrument was used to measure PEx in 126 healthy middle-aged nonsmoking subjects participating in the European Respiratory Community Health Survey (ERCS-III). The subjects performed a standardized breathing maneuver involving expiration to residual volume, a breath-hold of 3 seconds, a full inspiration, and then a full expiration into the PExA instrument. PEx number concentrations were expressed per exhalation and per exhaled liter. Age and anthropometric and spirometric variables were analyzed as potential predictors. Results: PEx/L was consistently and negatively associated to lung size-related variables and accordingly lower in men than in women. PEx/Exhalation was similar in women and men. Increasing age was associated with increasing PEx. Reference equations are presented based on age, weight, and spirometry variables and independent of sex. These predictors explained 28%-29% of the interindividual variation. Conclusions: The interindividual variation of PEx after a standardized breathing maneuver is large and the considered predictors explain a minor part only.
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| 2. |
- Kim, Jeong-Lim, et al.
(författare)
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Impact of occupational exposures on exacerbation of asthma: a population-based asthma cohort study.
- 2016
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Ingår i: BMC pulmonary medicine. - : Springer Science and Business Media LLC. - 1471-2466. ; 16:1
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Tidskriftsartikel (refereegranskat)abstract
- Asthma is a prevalent chronic disease and occupation contributes to approximately 15% of cases among adults. However, there are still few studies on risk factors for work-exacerbated asthma. The current study investigated the association between asthma exacerbations and occupational exposures.The study comprised all currently working adults (n=1356) who reported ever asthma in prior population-based cohorts. All subjects completed a questionnaire about exposures, occupations and exacerbations of asthma. Exposure to high and low molecular weight agents, irritating agents and asthmagens were classified using the asthma-specific job exposure matrix for northern Europe (N-JEM). Severe exacerbation of asthma was defined as sought emergency care at a hospital, admitted to a hospital overnight, or made an urgent visit to a primary care physician or district medical office due to breathing problems during the last 12months. Moderate exacerbation was defined as both being not severe exacerbation and an additional visit to a primary care physician or district medical office, or had extra treatments with corticosteroid tablets. Mild exacerbation was defined as being neither severe nor moderate exacerbation, and increasing usage of inhaled corticosteroids. Multiple logistic regression was applied to investigate the association between exacerbation of asthma and occupational exposures while adjusting for potential confounders.Approximately 26% of the working asthmatics reported exacerbation, and more than two-thirds of them had moderate or severe exacerbation. From 23 to 49% of the asthmatics reported occupational exposure to a variety of different types of agents. Exposure to any gas, smoke or dust (OR 1.7[95 % CI 1.2-2.6]) was associated with severe exacerbation of asthma, as were organic dust (OR 1.7[1.2-2.5]), dampness and mold (OR 1.8[1.2-2.7]), cold conditions (OR 1.7[1.1-2.7]), and a physically strenuous job (OR 1.6[1.03-2.3]). Asthmagens and low molecular weight agents classified by the N-JEM were associated with mild exacerbation, with OR 1.6[1.1-2.5] and OR 2.2[1.1-4.4], respectively.Self-reported exposure to any gas, smoke or dust, organic dust, dampness and mold, cold conditions and physically strenuous work, and jobs handling low molecular weight agents were associated with exacerbation of asthma. Reduction of these occupational exposures may help to reduce exacerbation of asthma.
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