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"Airflow obstruction"
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Evaluating the Relationship of Airflow Obstruction in COPD with Severity of OSA Among Patients with Overlap Syndrome
Background: Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) are common diseases affecting millions worldwide. These two diseases have a complex relationship that is not well understood. Previous small studies suggest an inverse relationship of disease severity of OSA with COPD airflow obstruction. Objective: The aim of this study was to determine if a relationship exists between severity of airflow obstruction in COPD and severity of OSA via apnea hypopnea index obtained during an in-lab baseline polysomnogram using a large quaternary care center cohort. Methods: From November 2015 through December 2018, 273 patients with confirmed COPD via spirometry and OSA via in-lab baseline polysomnogram were included. Conclusion: No associations were noted between severity of airflow obstruction in COPD and disease severity of OSA. Given the heterogeneity of these diseases, further exploration of a relationship within disease subtypes is warranted. Keywords: airflow obstruction, chronic obstructive pulmonary disease, obstructive sleep apnea
Journal Article
The Prevalence of Bronchodilator Responsiveness “Asthma” Among Adult Indigenous Australians Referred for Lung Function Testing in the Top End Northern Territory of Australia
Background: Among Indigenous Australians, studies examining the clinical significance of airway bronchodilator responsiveness (BDR) are limited. In this retrospective study, we examined the nature of underlying lung disease in adult Indigenous patients with BDR referred for lung function testing (LFT) in the Top End Health Service region of the Northern Territory of Australia. Methods: Presence or absence of BDR as per usual (FVC or FEV1 change pre to post [greater than or equal to]12% and [greater than or equal to]0.2L) and updated (2021 \">10% predicted) ATS/ERS criteria among Indigenous and non-Indigenous Australians was determined. The radiological findings in the Indigenous study participants with and without BDR were next assessed for the presence of underlying chronic airway/lung disease. Results: We found that 123/742 (17%) Indigenous and 578/4579 (13%) non-Indigenous patients had a significant BDR. Indigenous patients with BDR were younger (mean difference 7 years), with a greater proportion of females (52 vs 32%), underweight (15 vs 4%) and current smokers (52 vs 25%). Indigenous patients with BDR displayed lower LFT values, and a higher proportion exhibited FVC BDR compared to non-Indigenous (34 vs 20%). Almost half (46%) of Indigenous patients with BDR had evidence of COPD and/or bronchiectasis on radiology. Adjusting for the presence of radiologic or spirometric evidence of COPD, the presence of BDR was similar between Indigenous and non-Indigenous patients (5-8 vs 7-11%), irrespective of which BDR criteria was used. Conclusion: BDR was higher overall among Indigenous in comparison to non-Indigenous patients; however, a significant proportion of Indigenous patients demonstrating BDR had evidence of underlying COPD/bronchiectasis. This study highlights that although presence of BDR among Indigenous people may indicate asthma, it may also be observed among patients with COPD/bronchiectasis or could represent asthma/COPD/bronchiectasis overlap. Hence, a combination of clinical history, LFT and radiology should be considered for precise diagnosis of lung disease in this population. Keywords: asthma, airway obstruction, first nations, radiology imaging, reversible airflow obstruction, spirometry
Journal Article
Peripheral Blood Eosinophils and Nine Years Mortality in COPD Patients
Eosinophil counts increase during chronic obstructive pulmonary disease (COPD) exacerbation and influence the response to different agents (such as inhaled and systemic corticosteroids), as well as increase the production of other inflammatory cytokines. However, few studies have evaluated the association between peripheral blood eosinophils with mortality rate.
To evaluate the association between peripheral blood eosinophils and mortality rate in COPD patients over a nine-year period.
This cohort included 133 COPD patients assessed at baseline by spirometry, pulse oximetry (SpO
), complete blood count, body composition, dyspnea intensity [Modified Medical Research Council (mMRC)] and the six-minute distance test (6MWD). The Kaplan-Meier curve followed by a Log rank test was used to evaluate mortality rate related to eosinophil cutoff point categorization. Multivariate Cox regression analysis was performed to identify the association between eosinophils and mortality with all subjects evaluated at baseline, adjusted for age, gender, mMRC, 6MWT, forced expiratory volume in the first second (FEV
) and SpO
.
Nineteen patients did not complete follow-up and it was not possible to identify the date of death in four others. Therefore, 110 patients were included in the analysis. At baseline, 81% presented ≥150 eosinophil cells and 72% presented ≥2%. We identified a three-fold higher risk of death in those with <2% eosinophils and <150 cells. We did not identify statistical differences when using other cutoff points.
The decrease in number of peripheral eosinophils, with cutoff points at 2% and 150 cells, may be associated with a higher risk of death in COPD patients over nine years.
Journal Article
Occupational exposures to solvents and metals are associated with fixed airflow obstruction
Objectives This study investigated the associations between occupational exposures to solvents and metals and fixed airflow obstruction (AO) using post-bronchodilator spirometry. Methods We included 1335 participants from the 2002–2008 follow-up of the Tasmanian Longitudinal Health Study. Ever-exposure and cumulative exposure-unit (EU) years were calculated using the ALOHA plus job exposure matrix (JEM). Fixed AO was defined as post-bronchodilator forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) <0.7 and FEV1/FVC
Journal Article
Effects of Air Pollutant Exposure on Exacerbation Severity in Asthma Patients with or without Reversible Airflow Obstruction
Reversible airflow obstruction (RO) and fixed airflow obstruction (FO) are two important clinical phenotypes of asthma. However, the relationship between air pollutant exposure and exacerbation of the two phenotypes is unknown.
To study the effects of air pollutant exposure on exacerbation severity in asthma patients with or without FO.
A total of 197 severe asthma patients were enrolled, and divided into two groups: the FO group (n=81) and the RO group (n=116). We collected the demographic data, laboratory parameters, pulmonary function test parameters, and the daily average concentrations of different air particles in Shenzhen on the different lag days of each subject. The receiver operating characteristic (ROC) curve was used to identify the effects of major air pollutants on the severity of asthma patients with RO.
Compared with the RO group, the FO group had fewer women, lower body mass index (BMI), longer disease duration, higher smoking history rate, allergic family history rate, FeNO level, and lower levels of large airway parameters. The median exposure levels of PM10 and PM2.5 in the severe RO subgroup were both higher than those in the mild-to-moderate RO subgroup on Lag0, 1 and 3, and the median exposure level of PM1 on Lag0 in the severe RO subgroup was significantly higher than that in the mild-to-moderate RO subgroup. Logistic regression modeling indicated exposure to PM2.5 and PM1.0 on Lag0, and PM10 on Lag0-2 were the independent risk factors for hospital admissions for asthma patients with RO. By performing an ROC curve analysis, PM2.5 on Lag0 (AUC = 0.645,
= 0.027) provided a best performance to predict severe asthma exacerbations with RO, with a sensitivity of 36.0% and a specificity of 91.2%.
Short-term exposure to PM10, PM2.5 and PM1 may play a role in exacerbation severity among asthma patients with RO.
Journal Article
The Effect of Defining Chronic Obstructive Pulmonary Disease by the Lower Limit of Normal of FEV 1 /FVC Ratio in Tiotropium Safety and Performance in Respimat Participants
There is continuing debate about whether to define airflow obstruction by a post-bronchodilator ratio of forced expiratory volume in 1 second (FEV
) and forced vital capacity (FVC) below 0.70, or by ratio values falling below the age-dependent lower limit of normal (LLN) derived from general population data.
To determine whether using the LLN criterion affects the classification and outcomes of patients previously defined as having chronic obstructive pulmonary disease by the fixed FEV
/FVC ratio.
We applied the LLN definition to pooled data from the Tiotropium Safety and Performance in Respimat study that used the fixed FEV
/FVC ratio for the clinical diagnosis of chronic obstructive pulmonary disease.
A total of 17,072 patients were analyzed; of these, 1,807 (10.6%) patients had a ratio greater than or equal to LLN. Patients with a ratio greater than or equal to LLN had similar risks of death from any cause and fatal major adverse cardiovascular (CV) event as those below LLN. Patients with a ratio below LLN had a significantly lower risk of major adverse CV events (hazard ratio = 0.69; 95% confidence interval [CI] = 0.55-0.86; P = 0.001), and had significantly greater risks of moderate to severe exacerbation (rate ratio = 1.48; 95% CI = 1.36-1.61; P < 0.0001) and severe exacerbation (rate ratio = 2.01; 95% CI = 1.68-2.40; P < 0.0001) when compared with patients greater than or equal to LLN. Study outcomes by treatment arm (5 μg tiotropium Respimat vs. 18 μg HandiHaler) were comparable.
Using the LLN to define airflow obstruction would have excluded patients in the Tiotropium Safety and Performance in Respimat study with a higher risk of nonfatal major adverse CV events and a lower risk of exacerbation; study outcomes by treatment arm (2.5 μg/5 μg tiotropium Respimat vs. 18 μg HandiHaler) remained similar. Clinical trial registered with www.clinicaltrials.gov (NCT01126437).
Journal Article
Chronic Obstructive Pulmonary Disease and the Risk of Stroke. The Rotterdam Study
Worldwide, chronic obstructive pulmonary disease (COPD) and stroke are leading causes of death. Increasing evidence suggests an association between both diseases, either caused by an increased atherosclerosis risk in patients with COPD or as a consequence of shared risk factors between stroke and COPD.
To examine the associations between COPD and subtypes of stroke in the general population and to explore the role of cardiovascular risk factors and exacerbations on these associations.
Within the prospective population-based Rotterdam Study, we followed 13,115 participants without history of stroke for occurrence of stroke. Follow up started in 1990 to 2008 and ended in 2012. COPD was related to stroke using a time-dependent Cox proportional hazard model.
COPD was diagnosed in 1,566 participants. During 126,347 person-years, 1,250 participants suffered a stroke, of which 701 were ischemic and 107 hemorrhagic. Adjusted for age, age squared, and sex, COPD was significantly associated with all stroke (hazard ratio [HR], 1.20; 95% confidence interval, 1.00-1.43), ischemic stroke (HR, 1.27; 1.02-1.59), and hemorrhagic stroke (HR, 1.70; 1.01-2.84). Adjusting for cardiovascular risk factors gave similar effect sizes. In contrast, additional adjusting for smoking attenuated the effect sizes: HR, 1.09 (0.91-1.31) for all stroke; HR, 1.13 (0.91-1.42) for ischemic stroke; and HR 1.53 (0.91-2.59) for hemorrhagic stroke. After an acute severe exacerbation, subjects with COPD had a 6.66-fold (2.42-18.20) increased risk of stroke.
Our cohort study demonstrated a higher risk of both ischemic and hemorrhagic stroke in subjects with COPD and revealed the importance of smoking as a shared risk factor.
Journal Article
Airflow Obstruction and Use of Solid Fuels for Cooking or Heating. BOLD (Burden of Obstructive Lung Disease) Results
Evidence supporting the association of COPD or airflow obstruction with use of solid fuels is conflicting and inconsistent.
To assess the association of airflow obstruction with self-reported use of solid fuels for cooking or heating.
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.
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.
Airflow obstruction assessed from post-bronchodilator spirometry was not associated with use of solid fuels for cooking or heating.
Journal Article
Trajectories of Spirometric Patterns, Obstructive and PRISm, in a Population-Based Cohort in Latin America
Preserved ratio impaired spirometry (PRISm) has been associated with adverse outcomes and increased transition to other spirometric categories over time. We aimed to examine its prevalence, trajectories over time, and outcomes in a population-based sample from Latin America.
Data were obtained from two population-based surveys of adults from three cities in Latin America (PLATINO study), conducted on the same individuals 5-9 years after their baseline examination. We estimated the frequency of PRISm defined by FEV
/FVC≥0.70 with FEV
<80%, describing their clinical characteristics, longitudinal transition trajectories over time, factors associated with the transition.
At baseline, 2942 participants completed post-bronchodilator spirometry, and 2026 at both evaluations. The prevalence of normal spirometry was 78%, GOLD-stage 1 10.6%, GOLD 2-4 6.5%, and PRISm was: 5.0% (95% CI 4.2-5.8). PRISm was associated with less schooling, more reports of physician-diagnosis of COPD, wheezing, dyspnea, missing days at work, having ≥2 exacerbations in the previous year but without accelerated lung function decline. Mortality risk was significantly higher in PRISm (HR 1.97, 95% CI 1.2-3.3) and COPD GOLD 1-4 categories (HR 1.79, 95% CI 1.3-2.4) compared with normal spirometry. PRISm at baseline most frequently transitioned to another category at follow-up (46.5%); 26.7% to normal spirometry and 19.8% to COPD. The best predictors of transition to COPD were closeness of FEV
/FVC to 0.70, older age, current smoking, and a longer FET in the second assessment.
PRISm, is a heterogeneous and unstable condition prone to adverse outcomes that require adequate follow-up.
Journal Article
Female Smokers Are at Greater Risk of Airflow Obstruction Than Male Smokers. UK Biobank
The prevalence of chronic obstructive pulmonary disease (COPD) is increasing faster among women than among men.
To examine sex differences in the risk of airflow obstruction (a COPD hallmark) in relation to smoking history.
We analyzed 149,075 women and 100,252 men taking part in the UK Biobank who had provided spirometry measurements and information on smoking. The association of airflow obstruction with smoking characteristics was assessed by sex using regression analysis. The shape of this relationship was examined using restricted cubic splines.
The association of airflow obstruction with smoking status was stronger in women (odds ratio for ex-smokers [OR
], 1.44; OR
, 3.45) than in men (OR
, 1.25; OR
, 3.06) (P for interaction = 5.6 × 10
). In both sexes, the association of airflow obstruction with cigarettes per day, smoking duration, and pack-years did not follow a linear pattern, with the increase in risk at lower doses being steeper among women. For equal doses of exposure, sex differences were present in both ex-smokers and current smokers for cigarettes per day (P for interaction
= 6.0 × 10
; P for interaction
= 1.1 × 10
), smoking duration (P for interaction
= 7.9 × 10
; P for interaction
= 0.004), and pack-years (P for interaction
= 6.6 × 10
; P for interaction
= 1.3 × 10
). Overall, those who started smoking before age 18 years were more likely to have airflow obstruction, but a sex difference in this association was not clear. For equal time since quitting, the reduction in risk among women seemed less marked than among men.
Exposed to the same dose of smoking, women showed a higher risk of airflow obstruction than men. This could partly explain the increasingly smaller sex difference in the prevalence of COPD, especially in countries where smoking patterns have become similar between women and men.
Journal Article