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- Marcon, Alessandro, et al.
(author)
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Airway responsiveness to methacholine and incidence of COPD : an international prospective cohort study
- 2018
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In: Thorax. - : BMJ PUBLISHING GROUP. - 0040-6376 .- 1468-3296. ; 73:9, s. 825-832
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Journal article (peer-reviewed)abstract
- Background: It has been debated, but not yet established, whether increased airway responsiveness can predict COPD. Recognising this link may help in identifying subjects at risk.Objective: We studied prospectively whether airway responsiveness is associated with the risk of developing COPD.Methods: We pooled data from two multicentre cohort studies that collected data from three time points using similar methods (European Community Respiratory Health Survey and Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults). We classified subjects (median age 37 years, 1st–3rd quartiles: 29–44) by their level of airway responsiveness using quintiles of methacholine dose–response slope at the first examination (1991–1994). Then, we excluded subjects with airflow obstruction at the second examination (1999–2003) and analysed incidence of COPD (postbronchodilator FEV1/FVC below the lower limit of normal) at the third examination (2010–2014) as a function of responsiveness, adjusting for sex, age, education, body mass index, history of asthma, smoking, occupational exposures and indicators of airway calibre.Results: We observed 108 new cases of COPD among 4205 subjects during a median time of 9 years. Compared with the least responsive group (incidence rate 0.6 per 1000/year), adjusted incidence rate ratios for COPD ranged from 1.79 (95% CI 0.52 to 6.13) to 8.91 (95% CI 3.67 to 21.66) for increasing airway responsiveness. Similar dose–response associations were observed between smokers and non-smokers, and stronger associations were found among subjects without a history of asthma or asthma-like symptoms.Conclusions: Our study suggests that increased airway responsiveness is an independent risk factor for COPD. Further research should clarify whether early treatment in patients with high responsiveness can slow down disease progression.
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| 2. |
- Shaaban, Rafea, et al.
(author)
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Physical activity and bronchial hyperresponsiveness : European Community Respiratory Health Survey II
- 2007
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In: Thorax. - : BMJ. - 0040-6376 .- 1468-3296. ; 62:5, s. 403-410
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Journal article (peer-reviewed)abstract
- Background: Identification of the risk factors for bronchial hyperresponsiveness (BHR) would increase the understanding of the causes of asthma. The relationship between physical activity and BHR in men and women aged 28.0-56.5 years randomly selected from 24 centres in 11 countries participating in the European Community Respiratory Health Survey II was investigated. Methods: 5158 subjects answered questionnaires about physical activity and performed BHR tests. Participants were asked about the frequency and duration of usual weekly exercise resulting in breathlessness or sweating. BHR was defined as a decrease in forced expiratory volume in 1 s of at least 20% of its post-saline value for a maximum methacholine dose of 2 mg. Results: Both frequency and duration of physical activity were inversely related to BHR. The prevalence of BHR in subjects exercising ≤ 1, 2-3 and ≥4 times a week was 14.5%, 11.6% and 10.9%, respectively (p<0.001). The corresponding odds ratios were 1.00, 0.78 (95% Cl 0.62 to 0.99) and 0.69 (95% Cl 0.50 to 0.94) after controlling for potential confounding factors. The frequency of BHR in subjects exercising <1 h, 1-3 h and ≥4 h a week was 15.9%, 10.9% and 10.7%, respectively (p<0.001). The corresponding adjusted odds ratios were 1.00, 0.70 (95% Cl 0.57 to 0.87) and 0.67 (95% Cl 0.50 to 0.90). Physical activity was associated with BHR in all studied subgroups. Conclusions: These results suggest that BHR is strongly and independently associated with decreased physical activity. Further studies are needed to determine the mechanisms underlying this association.
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