Prevalence Of Airflow Obstruction Research Articles

Underdiagnosis of COPD: The Japan COPD Real-World Data Epidemiological (CORE) Study.

The prevalence of airflow obstruction in Japan is 3.8%-16.9%. This epidemiological study based on a large database aimed to reassess the prevalence of airflow obstruction in Japan and the diagnosis rate of chronic obstructive pulmonary disease (COPD). We used data regarding claims from the health insurance union and health checkups provided by JMDC. The present study included a subgroup of individuals aged ≥40 years who underwent health checkups involving spirometry between January and December 2019. The study endpoints were the prevalence of airflow obstruction, COPD diagnosis rate, disease stage, and respiratory function test results. Among 102,190 participants, 4113 (4.0%) had airflow obstruction. The prevalence of airflow obstruction was 5.3% in men and 2.1% in women. Among the study population, 6.8% were current smokers, while 3.4% were never or former smokers. Additionally, the prevalence of COPD increased with age. Approximately 8.4% of participants with airflow obstruction were diagnosed with COPD. Regarding the COPD diagnosis status, participants with airflow obstruction who were diagnosed with COPD were at a more advanced stage than those not diagnosed. Finally, patients diagnosed with COPD had significantly lower FEV1/FVC and FEV1 (p < 0.0001; Wilcoxon rank sum test). The epidemiological study based on a large database determined the COPD diagnosis rate related to airflow obstruction. The COPD diagnosis rate was extremely low among individuals who underwent health checkups, indicating the need for increased awareness about this medical condition. Moreover, primary care physicians should identify patients with suspected COPD and collaborate with pulmonologists to facilitate the early detection of COPD and enhance the COPD diagnosis rate.

Outcome-based Definition of the Lower Limit of Normal in Spirometry: A Study of 26,000 Young Adult Men.

Rationale The definition of the lower limit of normal (LLN) of spirometric variables is not well established. Objectives To investigate the relationship between spirometric abnormalities defined with different thresholds of the LLN and clinical outcomes, and to explore the possibility of using different LLN thresholds according to the pre-test probability of disease. Methods We studied the associations between pre-bronchodilator spirometric abnormalities (FEV1 < LLN, FVC < LLN, airflow obstruction, spirometric restriction) defined with different thresholds of the LLN (10th, 5th, 2.5th, 1st percentile) and multiple outcomes (prevalence of spirometric abnormalities, respiratory symptoms, all-cause and respiratory mortality) in 26,091 30-46 years old men who participated in a general population survey in Norway in 1988-1990 and were followed for 26 years. Analyses were performed with both local and GLI-2012 reference equations, stratified by pre-test risk (presence or absence of respiratory symptoms), and adjusted for age, BMI, smoking, and education. Results In the total population, the prevalence of airflow obstruction was 11.6% with GLI-LLN10, 11.0% with Local-LLN5, 6.1% with GLI-LLN5, 7.6% with Local-LLN2.5, and 3.5% with GLI-LLN2.5. The prevalence of spirometric restriction was 5.9% with GLI-LLN10, 5.2% with Local-LLN5, and 2.8% with GLI-LLN5. Increasingly lower thresholds of the LLN were associated with increasingly higher odds of respiratory symptoms and hazard of mortality for all spirometric abnormalities with both reference equations. Spirometric abnormalities defined with Local-LLN2.5 in asymptomatic subjects were associated with lower hazard of all-cause mortality (hazard ratio 1.50 (1.15, 1.95, 95% confidence intervals) for FEV1 < LLN) than those defined with Local-LLN5 in the general population (1.67 (1.50, 1.87) for FEV1 < LLN) and symptomatic subjects (1.67 (1.46, 1.91) for FEV1 < LLN). Overall, prevalence of spirometric abnormalities and associations with outcomes obtained with Local-LLN5 were comparable to those obtained with GLI-LLN10, and those obtained with Local-LLN2.5 to GLI-LLN5. Conclusions There is a relationship between statistically-based thresholds of the LLN of spirometric variables and clinical outcomes. Different thresholds of the LLN may be used in different risk subgroups of subjects, but the choice of the threshold needs to be evaluated together with the choice of reference equations.

Non-communicable airway disease and air pollution in three African Countries: Benin, Cameroon and The Gambia

&lt;sec id="st1"&gt;&lt;title&gt;BACKGROUND&lt;/title&gt;Air pollution exposure can increase the risk of development and exacerbation of chronic airway disease (CAD). We set out to assess CAD patients in Benin, Cameroon and The Gambia and to compare their measured exposures to air pollution.&lt;/sec&gt;&lt;sec id="st2"&gt;&lt;title&gt;METHODOLOGY&lt;/title&gt;We recruited patients with a diagnosis of CAD from four clinics in the three countries. We collected epidemiological, spirometric and home air pollution data.&lt;/sec&gt;&lt;sec id="st3"&gt;&lt;title&gt;RESULTS&lt;/title&gt;Of the 98 adults recruited, 56 were men; the mean age was 51.6 years (standard deviation ±17.5). Most (69%) patients resided in cities and ever smoking was highest in Cameroon (23.0%). Cough, wheeze and shortness of breath were reported across the countries. A diagnosis of asthma was present in 74.0%; 16.3% had chronic obstructive pulmonary disease and 4.1% had chronic bronchitis. Prevalence of airflow obstruction was respectively 77.1%, 54.0% and 64.0% in Benin, Cameroon, and Gambia. Across the sites, 18.0% reported &gt;5 exacerbations. The median home particulate matter less than 2.5 μm in diameter (PM2.5) was respectively 13.0 μg/m3, 5.0 μg/m3 and 4.4 μg/m3. The median home carbon monoxide (CO) exposures were respectively 1.6 parts per million (ppm), 0.3 ppm and 0.4 ppm. Home PM2.5 differed significantly between the three countries (P &lt; 0.001) while home CO did not.&lt;/sec&gt;&lt;sec id="st4"&gt;&lt;title&gt;CONCLUSION&lt;/title&gt;Based on these results, preventive programmes should focus on ensuring proper spirometric diagnosis, good disease control and reduction in air pollution exposure.&lt;/sec&gt;

GLI-12 Reference Values versus Fixed 0.7 Ratio for the Detection of Airflow Obstruction in the Presence of Lung Hyperinflation

Introduction: Airflow obstruction (AO) is evidenced by reduced forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) with the threshold for diagnosis often being set at <0.7. However, currently the ATS/ERS standards for interpretation of lung function tests recommend the lower limit of normal (LLN), calculated by reference equations of the Global Lung Initiative from 2012 (GLI-12), as a threshold for AO diagnosis. The present study aims to investigate phenotypes, with focus on hyperinflation, which influence AO prevalence defined by FEV1/FVC < LLN when compared to the fixed 0.7 threshold. Methods: Data from 3,875 lung function tests (56.4% men, aged 18–95) including 3,824 body plethysmography recordings performed from July 2021 to June 2022 were analysed. The difference between both classifiers was quantified, before and after stratification by sex, age, and hyperinflation. Results: AO diagnosis was significantly less frequent with the LLN threshold (18.2%) compared to the fixed threshold (28.0%) (p < 0.001) with discordance rate of 10.5%. In the presence of mild or moderate hyperinflation, there was substantial agreement (Cohen’s kappa: 0.616, 0.718) between the classifiers compared to near perfect agreement in the presence of severe hyperinflation (Cohen’s kappa: 0.896). In addition, subgroup analysis after stratification for sex, age, and hyperinflation showed significant differences between both classifiers. Conclusion: The importance of using the LLN threshold instead of the fixed 0.7 threshold for the diagnosis of AO is highlighted. When using the fixed threshold AO, misdiagnosis was more common in the presence of mild to moderate hyperinflation.

Phenotyping asthma with airflow obstruction in middle-aged and older adults: a CADSET clinical research collaboration

BackgroundThe prevalence and clinical profile of asthma with airflow obstruction (AO) remain uncertain. We aimed to phenotype AO in population- and clinic-based cohorts.MethodsThis cross-sectional multicohort study included adults ≥50 years...

Airflow obstruction and chronic obstructive pulmonary disease are common in pulmonary tuberculosis even without sequelae findings on chest X-ray

Purpose Pulmonary tuberculosis (TB) is a well-known risk factor for airflow obstruction and chronic obstructive pulmonary disease (COPD). The prognosis of TB without sequelae on chest X-ray (CXR) remains uncertain. Methods We used the 2008–2009 Korea National Health and Nutrition Examination Survey (KNHANES) data and 2007–2012 KNHANES-matched Health Insurance Review and Assessment Service cohort data. Airflow obstruction was assessed using a pulmonary function test. COPD was defined using diagnostic codes and the use of COPD medication for 3-year. We classified subjects into three groups based on TB history and sequelae on CXR. Results In 4911 subjects, the CXR(–) (no TB sequelae on CXR) post-TB group (n = 134) showed similar characteristics and normal lung function compared to that of the control group (n = 4,405), while the CXR(+) (TB sequelae on CXR) post-TB group (n = 372) showed different characteristics and reduced lung function. The prevalence of airflow obstruction was 9.3%, 13.4%, and 26.6% in control, CXR(-) post-TB, and CXR(+) post-TB groups, respectively. COPD was more common in the post-TB with CXR(+) (6.5%) or without CXR (–) (4.5%) groups, than in the control group (1.8%). Compared to the CXR(–) post-TB group, the control group showed a lower risk for airflow obstruction (OR, 0.774; p = .008). The CXR(+) post-TB group showed a higher risk for airflow obstruction (OR, 1.456; p = .011). The Control group also showed a lower risk for the development of COPD than the CXR(-) post-TB group (OR, 0.496; p = .011). Conclusions We need to educate TB patients that airway obstruction and COPD can easily develop, even if TB sequelae are not observed on CXR.

Prevalence of airflow obstruction in an apparently healthy population sample: a preliminary Italian study.

Prevalence of airflow obstruction in an apparently healthy population sample: a preliminary Italian study.

Staphylococcal Enterotoxin-Specific IgE Sensitization: A Potential Predictor of Fixed Airflow Obstruction in Elderly Asthma.

Staphylococcus aureus enterotoxin-specific immunoglobulin E (SE-sIgE) sensitization tends to increase with age and is known to be associated with asthma and severity in older adults. However, the long-term impact of SE-sIgE in the elderly remains unknown. This study aimed to examine the relationships between SE-sIgE and fixed airflow obstruction (FAO) in a cohort of elderly asthmatics. A total of 223 elderly asthmatics and 89 controls were analyzed. Patients were assessed for demographics, history of chronic rhinosinusitis (CRS), asthma duration, acute exacerbation frequency, and lung function at baseline and then were prospectively followed up for 2 years. Serum total IgE and SE-sIgE levels were measured at baseline. Airflow obstruction was defined as forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) ratio < 0.7 at baseline and FAO was defined as FEV1/FVC ratio < 0.7 over the 2-year follow-up. At baseline, the prevalence of airflow obstruction was 29.1%. Patients with airflow obstruction were significantly more likely to be male, and have a positive smoking history, comorbid CRS, and higher levels of SE-sIgE than those without airflow obstruction. Multivariate logistic regression analysis showed that airflow obstruction was significantly associated with current smoking and SE-sIgE sensitization at baseline. After the 2-year follow-up, baseline SE-sIgE sensitization was consistently related to FAO. Meanwhile, the number of exacerbations per year was significantly correlated with SE-sIgE levels. Baseline SE-sIgE sensitization was significantly associated with the number of asthma exacerbations and FAO after the 2-year follow-up in elderly asthmatics. These findings warrant further investigation of the direct and mediating roles of SE-sIgE sensitization on airway remodeling.

Associations Between Physical Activity, Smoking Status, and Airflow Obstruction and Self-Reported COPD: A Population-Based Study.

BackgroundChronic obstructive pulmonary disease (COPD) is a preventable and treatable disease with an increased mortality rate in recent years, mainly caused by exposure to tobacco smoke. Regular physical activity is thought to diminish the risk of COPD exacerbation, while very few studies investigate the interaction between smoking and physical activity on COPD development. This study aims to investigate the association between smoking status, physical activity and prevalent COPD.MethodsThis study analyzed data of adults 20 to 79 years old from the National Health and Nutrition Examination Survey (NHANES) 2007–2012.ResultsA total of 6404 participants aged 20–79 were included and divided into four groups by their physical activity levels and smoking status. Amongst, 2819 (43.7%) were physically active non-smokers, 957 (14.8%) were physically inactive non-smokers, 1952 (30.3%) were physically active smokers, and 717 (11.1%) were physically inactive smokers. Prevalence of airflow obstruction were 5.7%, 7.1%, 17.7% and 18.6%, respectively. After adjustment, physically active smokers (aOR=2.71, 95% CI=1.94–3.80) and physically inactive smokers (aOR=2.70, 95% CI=1.78–4.09) but not physically active non-smokers were more likely to have airflow obstruction than physically active non-smokers. These associations were similar among most subgroups by age, sex, or BMI. Among smokers, being physically inactive was not significantly associated with a greater chance for prevalent airflow obstruction than being physically active.ConclusionSmokers, regardless of their physical activity level, are more likely to have airflow obstruction as compared with physically active non-smokers. Within smokers, being physically inactive poses no excess chance to be airflow obstructed. The findings indicate that physical activity level seem not altering the relationship between smoking and airflow obstruction.

The burden of chronic respiratory diseases in adults in Nepal: A systematic review.

While chronic lung disease causes substantial global morbidity and mortality, global estimates have primarily been based on broad assumptions. Specific country data from low-income countries such as Nepal are limited. This review assessed primary evidence on chronic respiratory disease burden among adults in Nepal. A systematic search was performed in June 2019 (updated May 2020) for studies through nine databases. High levels of heterogeneity deemed a narrative synthesis appropriate. Among 27 eligible studies identified, most were low-moderate quality with cross-sectional and retrospective study design. Chronic lung diseases identified were chronic obstructive pulmonary disease (COPD), asthma, bronchiectasis and restrictive lung diseases. Studies were categorised as: (i) community-based, (ii) hospital-based and (iii) comorbidity-related and disease burden. Reported disease prevalence varied widely (COPD, 1.67–14.3%; asthma, 4.2–8.9%). The prevalence of airflow obstruction was higher among rural dwellers (15.8%) and those exposed to household air pollution from domestic biomass burning as opposed to liquid petroleum gas users (Odds Ratio: 2.06). Several comorbidities, including hypertension and diabetes mellitus added to the disease burden. The review shows limited literature on lung disease burden in Nepal. Publications varied in terms of overall quality. Good quality research studies with prospective cohorts related to respiratory conditions are required.

Prevalence and risk factors of airflow obstruction in a Caribbean population.

SETTING: The prevalence of airflow obstruction (AO) in the Caribbean population is unknown.OBJECTIVE: To measure the prevalence of and risk factors for AO (post-bronchodilator ratio of forced expiratory volume in 1 sec to forced vital capacity of <0.7) in the Trinidad and Tobago general population using the Burden of Obstructive Lung Disease methodology.DESIGN: National cross-sectional, stratified, cluster sampling of adults aged ≥40 years.RESULTS: AO prevalence was 9.5% among 1104 participants, most of whom were unaware of this. Compared to those aged 40-49 years, the adjusted odds ratio of AO by age group was 2.73 (60-69 years) and 3.30 (≥70 years). Risk factors for AO were unemployment (OR 4.31), being retired (OR 2.17), smoking ≥20 pack-years (OR 1.88) and exposure to dusty jobs for more than 1 year (OR 2.06). Related symptoms were history of wheezing, unscheduled visits to the doctor or admission to hospital for breathing problems and in subjects with at least one respiratory symptom (OR 1.90), at least one risk factor (OR 2.81), either symptoms or risk factors (OR 3.71) and both symptoms and risk factors (OR 5.78) (P < 0.05 in all cases).CONCLUSION: AO prevalence in the general population of Trinidad and Tobago aged ≥40 years was 9.5%, almost all of which was undiagnosed. AO was associated with smoking, age >59 years, lack of employment and working in a dusty job.

Prevalence of Airflow Obstruction as Measured by Spirometry, in Rural Southern Indian Adults

Rural population-based estimates of airflow obstruction based on spirometry are unavailable from southern India. This study assessed the prevalence of spirometry-defined airflow obstruction in Vellore, Tamil Nadu.A cross sectional survey was done in nine villages, among adults aged ≥30 years, where previous cardiovascular surveys had been conducted (1994, 2011). Population proportional to size sampling was used to select 20 clusters, with sampling from all streets proportional to the number of households. One person randomly selected per household was interviewed for symptoms and risk factors. A respiratory therapist performed pre and post bronchodilator spirometry on all, following American Thoracic Society criteria. Airflow obstruction was defined as pre-bronchodilator Forced Expiratory Volume 1 s/Forced Vital Capacity (FEV1/FVC) < Lower Limit of Normal (LLN, derived from local prediction equations) and compared to other criteria.Of 1015 participants, 787 completed technically acceptable spirometry. The prevalence of airflow obstruction was 9.0% (95% CI: 5.8%–9.6%, 71). Fixed obstruction (post bronchodilator FEV1/FVC < LLN) was 4.6% (95% CI: 3.1%–6.1%, 36), and 4.1% (95% CI: 2.7%–5.5%, 32) using post bronchodilator FEV1/FVC < 70%. The GOLD criteria missed 56% (40) of those with airflow obstruction, of which 87.5% were females. Although 63.4% with airflow obstruction had moderate to severe disease, 82.2% were not on treatment and only 48.9% reported symptoms in the previous year.This study estimates prevalence of airflow obstruction based on spirometry in rural southern India. Despite significant impairment on spirometry, majority were undiagnosed, and half did not report symptoms.

Prevalence, Awareness, and Associated Factors of Airflow Obstruction in Russia: The Ural Eye and Medical Study.

Background: Although chronic obstructive pulmonary disease and asthma belong to the most important causes of disability and death in all world regions, data about the prevalence of airflow obstruction and asthma in Russia and the associated parameters have been scarce so far. We therefore assessed the prevalence of airflow obstruction and asthma in a Russian population.Methods: The population-based Ural Eye and Medical Study, conducted in a rural and urban region of Bashkortostan/Russia, included 5,392 participants (mean age: 58.6 ± 10.6 years; range: 40–94 years) out of 7,328 eligible individuals. Airflow obstruction was defined spirometrically and asthma by self-reported diagnosis.Results: Airflow obstruction was present in 369 individuals (6.8%; 95% confidence interval (CI): 6.2, 7.5) with an awareness rate of 63.4% (95%CI: 58.5, 68.4) and known duration of 19.5 ± 15.8 years (median: 16 years). Prevalence of undiagnosed airflow obstruction was 2.6% (95%CI: 2.2, 3.1). Higher prevalence of airflow obstruction was associated (multivariable analysis) with higher prevalence of current smoking [P < 0.001; odds ratio (OR): 2.91; 95%CI: 1.76, 4.83] and number of cigarette package years (P < 0.001; OR: 1.03; 95%CI: 1.02, 1.08), female gender (P = 0.03; OR: 1.42; 95%CI: 1.04, 1.93), urban region (P = 0.003; OR: 1.43; 95% CI: 1.12, 1.79), higher prevalence of cardiovascular diseases/stroke (P < 0.001; OR: 1.86; 95%CI: 1.45, 2.39), higher depression score (P = 0.002; OR: 1.05; 95%CI: 1.02, 1.08), and lower physical activity (P = 0.01; OR: 0.71; 95%CI: 0.54, 0.93). Asthma prevalence (2.6%; 95%CI: 2.0, 3.1; known duration: 17.2 ± 15.0 years) was associated with less alcohol consumption (OR: 0.53; 95%CI: 0.33, 0.87; P = 0.01), higher depression score (OR: 1.08; 95%CI: 1.03, 1.12; P < 0.001), and urban region (OR: 0.68; 95CI: 0.49, 0.95; P = 0.0.03).Conclusions: In this Russian population aged 40+ years, the prevalence of airflow obstruction was 6.8% with an awareness rate of 63.4% and smoking as main risk factor. Asthma prevalence was 2.6%.

Respiratory Impairment and Personal Respirable Dust Exposure among the Underground and Open Cast Gold Miners in Tanzania.

Background:Mining is one of the most hazardous sectors to work in because it predisposes workers to various hazards including dust. Exposure to dust is inevitable in the mines because the process of extracting gold involves breaking rocks. This dust can penetrate up to the alveoli of the pulmonary system and cause respiratory impairment.Objectives:To determine respiratory impairment, personal respirable dust exposure levels and associated factors among miners in a gold mine in Tanzania.Methods:Cross-sectional study design, employing questionnaire, was used for data collection on respiratory symptoms. Lung functions were measured using spirometry. Personal respirable dust exposure was collected from similar exposure groups using air sampling pumps. A simple random sampling technique was used to select 112 participants of the study. Data analysis was done using SPSS computer software version 20.0.Results:The overall geometric mean (GM) of respirable dust was 0.26 mg/m3 (GSD = 0.32) over a mean sampling time of 8 hours (with a range between 7–11 hours). The GM of respirable dust for underground workers was significantly higher (0.41 ± 0.28 mg/m3) compared to the open pit workers (0.17 ± 0.23 mg/m3) with p < 0.01. For underground workers, the GM of respirable dust was the highest among the bogger operators at 0.53 mg/m3 (GSD = 0.27). For open pit workers, the highest GM of respirable dust was found among the quality controllers at 0.39 mg/m3 (GSD = 0.18). Respiratory symptoms were phlegm (49.1%), breathlessness (42.9%), cough (37.5%), wheezing (18.8%) and chest tightness (10.7%). Cigarette smokers were more likely to suffer from breathlessness than nonsmokers. The prevalence of airflow obstruction (FEV1/FVC < 0.7) was 1.9%; whereas, the prevalence of lung restriction was 8.8%. The study established that age, smoking habit and previous exposure to dust could not predict lung function impairment.Conclusion:Despite levels of respirable dust exposure being below the recommended occupational exposure limits, the prevalence of respiratory symptoms was still found to be high among the studied gold miners. This calls for a need to conduct further studies on quartz content of the respirable dust.

Prevalence of airflow obstruction in patients with stable systolic heart failure

BackgroundChronic obstructive pulmonary disease (COPD) is an important differential diagnosis in heart failure (HF). However, routine use of spirometry in outpatient HF clinics is not implemented. The aim of the present study was to determine the prevalence of both airflow obstruction and non obstructive lung function impairment in patients with HF and to examine the effect of optimal medical treatment for HF on lung function parameters.MethodsConsecutive patients with HF (ejection fraction (EF) < 45%) and New York Heart Association (NYHA) functional class II-IV at 10 different outpatient heart failure clinics were examined with spirometry at their first visit and after optimal medical treatment for HF was achieved. airflow obstruction was classified and graded according to the GOLD 2011 revision.ResultsBaseline spirometry was performed in 593 included patients and 71 (12%) had a clinical diagnosis of COPD. Mean age was 69 ± 11 years and mean EF was 30 ± 9%. Thirty-two % of the patients were active smokers and 53% were previous smokers. Mean FEV1 and FVC was 77.9 ± 1.7% and 85.4 ± 1.5% of predicted respectively. Obstructive pattern was observed in 233 (39%) of the patients. Of these, 53 patients (9%) had mild disease (GOLD I) and 180 (30%) patients had moderate to very severe disease (GOLD II-IV). No difference in spirometric variables was observed following up titration of medication.ConclusionIn stable patients with HF airflow obstruction is frequent and severely underdiagnosed. Spirometry should be considered in all patients with HF in order to improve diagnosis and treatment for concomitant pulmonary disease.

Clinically remitted childhood asthma is associated with airflow obstruction in middle-aged adults.

While adult asthma has been shown to be a risk factor for COPD, the effect of remitted childhood asthma on adult lung function has not been clarified. The aim of this study was to examine whether remitted childhood asthma is a risk factor for airflow obstruction in a middle-aged general population. A total of 9896 participants (range: 35-60 years) from five healthcare centres were included in the study. The participants were classified into four categories based on the presence or absence of physician-diagnosed childhood/adulthood asthma and asthma symptoms as follows: healthy controls (n = 9154), remitted childhood asthma (n = 287), adulthood-onset asthma (n = 354) and childhood-adulthood asthma (n = 101). The prevalence of respiratory symptoms was similar in both the participants with remitted childhood asthma and healthy controls. The prevalence of airflow obstruction (forced expiratory volume in 1 s (FEV1 )/forced vital capacity (FVC) < 0.7) was significantly higher in the participants with remitted childhood asthma, those with adult-onset asthma and those with childhood-adulthood asthma (5.2%, 14.4% and 16.8%, respectively) compared with healthy controls (2.2%). Multivariate logistic regression showed that remitted childhood asthma was independently associated with airflow obstruction. Among the participants with remitted childhood asthma, ever-smokers had significantly lower FEV1 /FVC than never-smokers. Clinically remitted childhood asthma is associated with airflow obstruction in middle-aged adults. Smoking and remitted childhood asthma may be additive factors for the development of airflow obstruction.

The Prevalence of Chronic Obstructive Pulmonary Disease by the Global Lung Initiative Equations in North-Western Russia

Background: The prevalence of chronic obstructive pulmonary disease (COPD) varies in different countries, while the cut-off for airflow obstruction (AO) is still contested. No COPD prevalence data based on the Global Lung Initiative (GLI) 2012 equations are available in Russia. Objectives: This study aims to assess AO prevalence by the GLI lower limit of normal (GLI-LLN) and the fixed cut-off, to identify AO risk factors and to assess the diagnostic value of respiratory symptoms in north-western Russia. Methods: In a north-western Russian population-based sample of 2,974 adults aged 35-70 years, data on socio-demographics, smoking, occupational exposures and respiratory symptoms were collected, and spirometry was performed before and after bronchodilator (BD) administration. Results: The AO prevalence was 6.8% (95% CI 5.8-7.9) based on the fixed and 4.8% (95% CI 3.9-5.7) based on the GLI-LLN cut-off. 22.5% of the participants with post-BD AO had a positive bronchodilator test, and 1% showed a paradoxical BD response. Of the environmental factors studied, only smoking was independently associated with AO (odds ratio 2.47, 95% CI 1.60-3.82). The positive predictive value of respiratory symptoms for AO was 11% based on the fixed and 8% based on the GLI-LLN cut-off. Conclusions: In a sample of adults in north-western Russia, the AO prevalence by the GLI-LLN cut-off was lower than that by the fixed cut-off. The predictive value of respiratory symptoms was low.

Prevalence of airflow obstruction according GOLD, ATS and ERS criteria in symptomatic ever-smokers referring to a Pulmonary Rehabilitation Department

To evaluate in a Pulmonary Rehabilitation (PR) setting the prevalence of airflow obstruction (AO) in either current or former smokers > or = 45 years old both with dyspnoea and with chronic productive cough, using European Respiratory society (ERS) statement (FEV1/SVC < 88 and < 89% predicted in men and women, respectively), American Thoracic Society (ATS) statement (FEV1/FVC < 75%), and Global Initiative for Chronic Obstructive Lung Disease (GOLD) statement (FEV1/FVC < 70%). Lung function tests were performed in each patient who was referred to our PR department due to respiratory diagnosis or symptoms. For analysis, in patients showing AO we used post-bronchodilator lung function values. In 184 ever-smoker patients with symptoms of chronic obstructive pulmonary disease (COPD), the prevalence rates of AO were as follows: ERS = 89.7%, ATS = 76.6%, and GOLD = 63.6%. Patients with AO according ERS criteria showing moderate to severe (M/S) obstruction (i.e., FEV1 < 70% predicted) were 119. Patients with ERS M/S AO but without AO using either ATS or GOLD criteria were 8.4% and 19.3%, respectively. Prevalence of AO is highly dependent on which guidelines it is based. ATS and particularly GOLD statement can cause a large under-diagnosis even of moderate to severe COPD. Diagnosis of COPD may be overlooked if SVC is not performed.

Area specific differences in lung function indices and prevalence of airflow obstruction in adults: findings from people in 10 areas in China

To describe the area specific differences in lung function indices and prevalence of airflow obstruction (AFO) in adults found by China Kadoorie Biobank (CKB) study, involving 512 495 adults, in 10 areas in China. The detailed information on lung function indices (FEV, and FVC) and prevalence of AFO (diagnosed according to GOLD and LLN criteria) of subjects aged 30-79 years were analyzed, those with abnormal lung function indices at baseline survey were excluded. The FEV1 and FVC among males (2.66 L, 3.16 L) were higher than those among females (1.99 L, 2.35 L). The FEV1 and FVC were highest in Henan and Harbin. The prevalence of AFO diaonosed according to GOLD criteria was 5.13% in males, higher than that in females (3.75%). The prevalence of AFO was higher in rural area than in urban area (males: 6.32% vs. 3.47%; females: 4.26% vs. 2.97%). The prevalence of AFO was highest in Sichuan (13.34% in males, 10.70% in females), followed by that in Suzhou, Henan and Hunan. The prevalence of AFO diagnosed according to LLN criteria (6.93% in males, 6.29% in females) was higher than that diagnosed according to GOLD criteria, but the area specific difference was similar. The lung function indices and the prevalence of AFO in adults varied greatly among the 10 areas covered by CKB study.

Prevalence of airflow obstruction and reduced forced vital capacity in an Aboriginal Australian population: The cross-sectional BOLD study.

Mortality and hospital separation data suggest a higher burden of chronic obstructive pulmonary disease (COPD) in indigenous than non-indigenous subpopulations of high-income countries. This study sought to accurately measure the true prevalence of post-bronchodilator airflow obstruction and forced vital capacity reduction in representative samples of Indigenous and non-Indigenous Australians. This study applies cross-sectional population-based survey of Aboriginal and non-Indigenous residents of the Kimberley region of Western Australia aged 40 years or older, following the international Burden Of Lung Disease (BOLD) protocol. Quality-controlled spirometry was conducted before and after bronchodilator. COPD was defined as Global initiative for chronic Obstructive Lung Disease (GOLD) Stage 2 and above (post-bronchodilator forced expiratory volume in 1 s/forced vital capacity (FEV1 /FVC) ratio <0.7 and FEV1 < 80% predicted). Complete data were available for 704 participants. The prevalence of COPD, adjusted for age, gender and body weight in Aboriginal participants (7.2%, 95% confidence interval (CI) 3.9 to 10.4) was similar to that seen in non-Indigenous Kimberley participants (8.2%, 95% CI 5.7 to 10.7) and non-Indigenous residents of the remainder of Australia (7.1%, 95% CI 6.1 to 8.0). The prevalence of low FVC (<80% predicted) was substantially higher in Aboriginal compared with non-Indigenous participants (74.0%, 95% CI 69.1 to 78.8, vs 9.7%, 95% CI 7.1 to 12.4). Low FVC, rather than airflow obstruction, characterizes the impact of chronic lung disease previously attributed to COPD in this population subject to significant social and economic disadvantage. Environmental risk factors other than smoking as well as developmental factors must be considered. These findings require further investigation and have implications for future prevention of chronic lung disease in similar populations.