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Background and objective: Lack of consensus on diagnosis of ACO limits our understanding of the impact, management and outcomes of ACO. The present observational study aims to describe the prevalence, clinical characteristics and course of individuals with ACO based on various definitions used in clinical practice. Methods: We included individuals with COPD from the prospective, multisite CanCOLD study and defined subjects with ACO using seven definitions commonly used in the literature. Results: Data including questionnaires, lung function and CT scans were analysed from 522 individuals with COPD who were randomly recruited from the population. Among them, 264 fulfilled at least one of the seven definitions of ACO. Prevalence of ACO varied from 3.8% to 31%. Regardless of the definition, individuals with ACO had worse outcomes (lung function and higher percentage of fast decliners, symptoms and exacerbations, health‐related quality of life and comorbidities) than the remaining patients with COPD. Conversely, patients with non‐ACO had higher emphysema and bronchiolitis scores. The three definitions that included atopy and/or physician diagnosis of asthma identified subjects who differed significantly from patients with COPD. The two ACO definitions with post‐bronchodilator reversibility were concordant with COPD and were the least stable, with less than 50% of the patients from each group maintaining reversibility over visits. Conclusion: Atopy and physician‐diagnosed asthma are more distinguishing characteristics to identify ACO. This finding needs to be validated using measures of airway inflammation and other specific biomarkers. [ABSTRACT FROM AUTHOR]

A high prevalence of intermediate cardiometabolic risk factors and obesity in chronic obstructive pulmonary disease (COPD) has suggested the existence of pathophysiological links between hypertriglyceridemia, insulin resistance, visceral adiposity, and hypoxia or impaired pulmonary function. However, whether COPD contributes independently to the development of these cardiometabolic risk factors remains unclear. Our objective was to compare ectopic fat and metabolic profiles among representative individuals with COPD and control subjects and to evaluate whether the presence of COPD alters the metabolic risk profile. Study participants were randomly selected from the general population and prospectively classified as non-COPD controls and COPD, according to the Global Initiative for Chronic Obstructive Lung Disease classification. The metabolic phenotype, which consisted of visceral adipose tissue area, metabolic markers including homeostasis model assessment of insulin resistance (HOMA-IR), and blood lipid profile, was obtained in 144 subjects with COPD and 119 non-COPD controls. The metabolic phenotype was similar in COPD and controls. The odds ratios for having pathologic values for HOMA-IR, lipids and visceral adipose tissue area were similar in individuals with COPD and control subjects in multivariate analyses that took into account age, sex, body mass index, tobacco status and current medications. In a population-based cohort, no difference was found in the metabolic phenotype, including visceral adipose tissue accumulation, between COPD and controls. Discrepancies between the present and previous studies as to whether or not COPD is a risk factor for metabolic abnormalities could be related to differences in COPD phenotype or disease severity of the study populations. [ABSTRACT FROM AUTHOR]

The article describes how forced expiratory volume in one second/forced vital capacity (FEV1/FVC) ratio discordance relates to functional outcomes relevant to subjects' daily functioning. Topics include the fixed FEV1/FVC ratio cutoff can result in over diagnosis of Chronic obstructive pulmonary disease (COPD) in older individuals; and a discordant FEV1/FVC ratio should be individually interpreted in light of clinical data.

Introduction: Pneumonia is associated with considerable mortality. However, there is limited information on age-specific prognostic factors for death from pneumonia.Methods: Patients hospitalised with a diagnosis of pneumonia through the emergency department were stratified into three age groups: 18-64 years, 65-84 years and ≥ 85 years. Multivariate logistic regression and receiver operating characteristic curve analyses were conducted to evaluate prognostic factors for mortality and the performance of pneumonia severity scoring tools for mortality prediction.Results: A total of 1,902 patients were enrolled (18-64 years: 614 [32.3%]; 65-84 years: 944 [49.6%]; ≥ 85 years: 344 [18.1%]). Mortality rates increased with age (18-64 years: 7.3%; 65-84 years: 16.1%; ≥ 85 years: 29.7%; p < 0.001). Malignancy and tachycardia were prognostic of mortality among patients aged 18-64 years. Male gender, malignancy, congestive heart failure and eight other parameters reflecting acute disease severity were associated with mortality among patients aged 65-84 years. For patients aged ≥ 85 years, altered mental status, tachycardia, blood urea nitrogen, hypoxaemia, arterial pH and pleural effusion were significantly predictive of mortality. The Pneumonia Severity Index (PSI) was more sensitive than CURB-65 (confusion, uraemia, respiratory rate ≥ 30 per minute, low blood pressure, age ≥ 65 years) for mortality prediction across all age groups.Conclusion: The predictive effect of prognostic factors for mortality varied among patients with pneumonia from the different age groups. PSI performed significantly better than CURB-65 for mortality prediction, but its discriminative power decreased with advancing age. [ABSTRACT FROM AUTHOR]

Rationale: Evidence supporting the association of COPD or airflow obstruction with use of solid fuels is conflicting and inconsistent.Objective: To assess the association of airflow obstruction with self-reported use of solid fuels for cooking or heating.Methods: We analysed 18,554 adults from the BOLD study, who had provided acceptable post-bronchodilator spirometry measurements and information on use of solid fuels. The association of airflow obstruction with use of solid fuels for cooking or heating was assessed by sex, within each site, using regression analysis. Estimates were stratified by national income and meta-analysed. We carried out similar analyses for spirometric restriction, chronic cough and chronic phlegm.Measurements and Main Results: We found no association between airflow obstruction and use of solid fuels for cooking or heating (ORmen=1.20, 95%CI 0.94-1.53; ORwomen=0.88, 95%CI 0.67-1.15). This was true for low/middle and high income sites. Among never smokers there was also no evidence of an association of airflow obstruction with use of solid fuels (ORmen=1.00, 95%CI 0.57-1.76; ORwomen=1.00, 95%CI 0.76-1.32). Overall, we found no association of spirometric restriction, chronic cough or chronic phlegm with the use of solid fuels. However, we found that chronic phlegm was more likely to be reported among female never smokers and those who had been exposed for ≥20 years.Conclusion: Airflow obstruction assessed from post-bronchodilator spirometry was not associated with use of solid fuels for cooking or heating. [ABSTRACT FROM AUTHOR]

Background: Disease accumulates in the small airways without being detected by conventional measurements. Objectives: To quantify small airway disease using a novel computed tomography (CT) inspiratory-to-expiratory approach called the disease probability measure (DPM) and to investigate the association with pulmonary function measurements. Methods: Participants from the population-based CanCOLD study were evaluated using full-inspiration/full-expiration CT and pulmonary function measurements. Full-inspiration and full-expiration CT images were registered, and each voxel was classified as emphysema, gas trapping (GasTrap) related to functional small airway disease, or normal using two classification approaches: parametric response map (PRM) and DPM (VIDA Diagnostics, Inc., Coralville, IA, USA). Results: The participants included never-smokers (n = 135), at risk (n = 97), Global Initiative for Chronic Obstructive Lung Disease I (GOLD I) (n = 140), and GOLD II chronic obstructive pulmonary disease (n = 96). PRMGasTrap and DPMGasTrap measurements were significantly elevated in GOLD II compared to never-smokers (p < 0.01) and at risk (p < 0.01), and for GOLD I compared to at risk (p < 0.05). Gas trapping measurements were significantly elevated in GOLD II compared to GOLD I (p < 0.0001) using the DPM classification only. Overall, DPM classified significantly more voxels as gas trapping than PRM (p < 0.0001); a spatial comparison revealed that the expiratory CT Hounsfield units (HU) for voxels classified as DPMGasTrap but PRMNormal (PRMNormal- DPMGasTrap = -785 ± 72 HU) were significantly reduced compared to voxels classified normal by both approaches (PRMNormal-DPMNormal = --722 ± 89 HU; p < 0.0001). DPM and PRM GasTrap measurements showed similar, significantly associations with forced expiratory volume in 1 s (FEV1) (p < 0.01), FEV1/forced vital capacity (p < 0.0001), residual volume/total lung capacity (p < 0.0001), bronchodilator response (p < 0.0001), and dyspnea (p < 0.05). Conclusion: CT inspiratory-to-expiratory gas trapping measurements are significantly associated with pulmonary function and symptoms. There are quantitative and spatial differences between PRM and DPM classification that need pathological investigation. [ABSTRACT FROM AUTHOR]

Background: Recommendations on interpreting tests of bronchodilator responsiveness (BDR) are conflicting. We investigated the dependence of BDR criteria on sex, age, height, ethnicity, and severity of respiratory impairment.Methods: BDR test data were available from clinical patients in the Netherlands, New Zealand, and the United States (n = 15,278; female subjects, 51.7%) and from surveys in Canada, Norway, and five Latin-American countries (n = 16,250; female subjects, 54.7%). BDR calculated according to FEV1, FVC, and FEV1/FVC was expressed as absolute change, a percentage of the baseline level (% baseline), a percentage of the predicted value (% predicted), and z score.Results: Change (Δ) in FEV1 and FVC, in milliliters, was unrelated to the baseline value but was biased toward age, height, sex, and level of airways obstruction; ΔFEV1 was significantly lower in African Americans. In 1,106 subjects with low FEV1 (200-1,621 mL) the FEV1 increased by 12% to 44.7% relative to baseline but < 200 mL. Expressing BDR as a percentage of the predicted value or as a z score attenuated the bias and made the 200-mL criterion redundant, but reduced positive responses by half. ΔFEV1 % baseline increased with the level of airflow obstruction but decreased with severe obstruction when expressed as z scores or % predicted; ΔFVC, however expressed, increased with the level of airflow obstruction.Conclusions: Expressing FEV1 responsiveness as % baseline spuriously suggests that responsiveness increases with the severity of respiratory impairment. Expressing change in FEV1 or FVC as % predicted or as z scores eliminates this artifact and renders the required 200-mL minimum increase redundant. In severe airways obstruction ΔFVC should be critically evaluated as an index of clinically important relief of hyperinflation, with implications for bronchodilator drug trials. [ABSTRACT FROM AUTHOR]

Background: Thoracic computed tomography (CT) scans are widely performed in clinical practice, often leading to detection of airway or parenchymal abnormalities in asymptomatic or minimally symptomatic individuals. However, clinical relevance of CT abnormalities is uncertain in the general population. Methods: We evaluated data from 1361 participants aged ≥40 years from a Canadian prospective cohort comprising 408 healthy never-smokers, 502 healthy ever-smokers, and 451 individuals with spirometric evidence of chronic obstructive pulmonary disease (COPD) who had thoracic CT scans. CT images of subjects were visually scored for respiratory bronchiolitis(RB), emphysema(E), bronchial-wall thickening(BWT), expiratory air-trapping(AT), and bronchiectasis(B). Multivariable logistic regression models were used to assess associations of CT features with respiratory symptoms, dyspnea, health status as determined by COPD assessment test, and risk of clinically significant exacerbations during 12 months follow-up. Results: About 11% of life-time never-smokers demonstrated emphysema on CT scans. Prevalence increased to 30% among smokers with normal lung function and 36%, 50%, and 57% among individuals with mild, moderate or severe/very severe COPD, respectively. Presence of emphysema on CT was associated with chronic cough (OR,2.11; 95%CI,1.4–3.18); chronic phlegm production (OR,1.87; 95% CI,1.27–2.76); wheeze (OR,1.61; 95% CI,1.05–2.48); dyspnoea (OR,2.90; 95% CI,1.41–5.98); CAT score≥10(OR,2.17; 95%CI,1.42–3.30) and risk of ≥2 exacerbations over 12 months (OR,2.17; 95% CI, 1.42–3.0). Conclusions: Burden of thoracic CT abnormalities is high among Canadians ≥40 years of age, including never-smokers and smokers with normal lung function. Detection of emphysema on CT scans is associated with pulmonary symptoms and increased risk of exacerbations, independent of smoking or lung function. [ABSTRACT FROM AUTHOR]