COPD
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Whether respiratory symptoms are associated with mortality independent of lung function is unclear. The authors explored the association of the exposures i) lung function, ii) respiratory symptoms, and iii) lung function and respiratory symptoms combined, with the outcomes all-cause and cardiovascular mortality. The study included 10,491 adults who participated in the Nord-Trøndelag Health Study (HUNT) Lung Study in 1995-1997 and were followed through 2009. ⋯ Analyses of lung function and dyspnoea when walking as a combined exposure further supported this finding. Overall, associations between lung function and cardiovascular mortality were weaker, and respiratory symptoms were not associated with cardiovascular mortality. In conclusion, lung function was inversely associated with all-cause and cardiovascular mortality, and dyspnoea when walking was associated with all-cause mortality independent of lung function.
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Minimum clinically important change of 5 points in the University of California, San Diego Shortness of Breath Questionnaire (SOBQ) is established, but cutoff values between a small, a moderate, and a large change are still unknown. We used the data set of National Emphysema Treatment Trial consisting of severe and very severe chronic obstructive pulmonary disease patients, whose mean age was 64 years. Changes from baseline to post-surgical 6-month follow-up were evaluated. ⋯ In a cohort of surgically treated patients (N = 484), we propose value of 5 (range 5-6), 11 (range 9-15), and 16 (range 14-20) for the cutoff values between a meaningless and a small change (minimum clinically important difference), a small and a moderate change, and a moderate and a large change, respectively. In a cohort of medically treated patients, numbers of patients categorized according to ∆SOBQ scores were similar to those of the patients categorizes according to the ∆SGRQ (N = 480) or ∆Forced expiratory volume in 1 second (N = 425). We propose group-level cutoff values and range between a small, a moderate, and a large changes.
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Oxidative stress is implicated in the pathogenesis of asthma and chronic obstructive pulmonary disease (COPD). Analysis of the expired breath condensate (EBC) has been suggested to provide non-invasive inflammatory markers that reflect oxidative stress in the airways. ⋯ These findings suggest that oxidative stress is involved in the pathogenesis of asthma and COPD and that the H2O2 levels in EBC might reflect the health status in COPD.
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Progressive decline in lung function has been widely accepted as the hallmark of chronic obstructive pulmonary disease (COPD); however, recent evidence indicates that the rate of decline measured as decline in forced expiratory volume in one second (FEV1) is higher in mild to moderate COPD than in severe COPD. Usually changes in FEV1 are measured in ml that is "absolute"; however, changes can also be measured "relative" as a percentage of the actual FEV1. We hypothesize that relative measurements could be more appropriate than absolute measurements for describing changes in lung function. ⋯ Measuring changes in relative terms could have important implications for the interpretation of results from clinical trials where FEV1 is the primary outcome. DLCST; www. ClinicalTrials.org , registration number: NCT00496977.
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Randomized Controlled Trial
Severe chronic bronchitis in advanced emphysema increases mortality and hospitalizations.
Chronic bronchitis in COPD has been associated with an increased exacerbation rate, more hospitalizations, and an accelerated decline in lung function. The clinical characteristics of patients with advanced emphysema and chronic bronchitis have not been well described. ⋯ Severe chronic bronchitis is associated with worse survival, shorter time to hospitalization, and worse health-related quality of life.