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Rationale It remains unknown whether long-term ozone exposure can impair lung function. Objectives To investigate the associations between long-term ozone exposure and adult lung function in China. Methods Lung function results and diagnosis of small airways dysfunction (SAD) were collected from a cross-sectional study, China Pulmonary Health Study (N=50,991). We used multivariate linear and logistic regression models to examine the associations of long-term ozone exposure with lung function parameters and SAD, respectively, adjusting for demographic characteristics, individual risk factors, and longitudinal trend. We then performed a stratification analysis by chronic obstructive pulmonary disease (COPD). Measurements and main results We observed each 1-standard deviation (SD, 4.9 ppb) increase in warm-season ozone concentrations was associated with a 14.2 mL/s [95% confidence interval (CI): 8.8, 19.6] decrease in forced expiratory flow at 75th percentile of vital capacity and a 29.5 mL/s (95% CI: 19.6, 39.5) decrease in mean forced expiratory flow between the 25th and 75th percentile of vital capacity. The odds ratio of SAD was 1.09 (95% CI: 1.06, 1.11) for a 1-SD increase in warm-season ozone concentrations. Meanwhile, we observed a significant association with a decreased ratio of expiratory volume in 1 second to forced vital capacity (FEV1/FVC) but not with FEV1 or FVC. The association estimates were greater in the COPD group than in the non-COPD group. Conclusion We found independent associations of long-term ozone exposure with impaired small airways function and higher SAD risks, while the associations with airflow obstruction were weak. COPD patients appear to be more vulnerable.

Summary Background Although exposure to cigarette smoking and air pollution is common, the current prevalence of chronic obstructive pulmonary disease (COPD) is unknown in the Chinese adult population. We conducted the China Pulmonary Health (CPH) study to assess the prevalence and risk factors of COPD in China. Methods The CPH study is a cross-sectional study in a nationally representative sample of adults aged 20 years or older from ten provinces, autonomous regions, and municipalities in mainland China. All participants underwent a post-bronchodilator pulmonary function test. COPD was diagnosed according to 2017 Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria. Findings Between June, 2012, and May, 2015, 57 779 individuals were invited to participate, of whom 50 991 (21 446 men and 29 545 women) had reliable post-bronchodilator results and were included in the final analysis. The overall prevalence of spirometry-defined COPD was 8·6% (95% CI 7·5–9·9), accounting for 99·9 (95% CI 76·3–135·7) million people with COPD in China. Prevalence was higher in men (11·9%, 95% CI 10·2–13·8) than in women (5·4%, 4·6–6·2; p 3 (1·85, 1·23–2·77) or 75 μg/m 3 or higher (2·00, 1·36–2·92), underweight (body-mass index 2 ; 1·43, 1·03–1·97), sometimes childhood chronic cough (1·48, 1·14–1·93) or frequent cough (2·57, 2·01–3·29), and parental history of respiratory diseases (1·40, 1·23–1·60). A lower risk of COPD was associated with middle or high school education (OR 0·76, 95% CI 0·64–0·90) and college or higher education (0·47, 0·33–0·66). Interpretation Spirometry-defined COPD is highly prevalent in the Chinese adult population. Cigarette smoking, ambient air pollution, underweight, childhood chronic cough, parental history of respiratory diseases, and low education are major risk factors for COPD. Prevention and early detection of COPD using spirometry should be a public health priority in China to reduce COPD-related morbidity and mortality. Funding Ministry of Health and Ministry of Science and Technology of China.

OBJECTIVES To investigate the relationships between fractional exhaled nitric oxide (FENO) and clinical characteristics and outcomes in patients with subacute cough. METHODS Patients with subacute cough (n = 189) after upper respiratory tract infection were enrolled in this single-center prospective study, and were divided into low-FENO (

Summary Background Small airway dysfunction is a common but neglected respiratory abnormality. Little is known about its prevalence, risk factors, and prognostic factors in China or anywhere else in the world. We aimed to estimate the prevalence of small airway dysfunction using spirometry before and after bronchodilation, both overall and in specific population subgroups; assess its association with a range of lifestyle and environmental factors (particularly smoking); and estimate the burden of small airway dysfunction in China. Methods From June, 2012, to May, 2015, the nationally representative China Pulmonary Health study invited 57 779 adults to participate using a multistage stratified sampling method from ten provinces (or equivalent), and 50 479 patients with valid lung function testing results were included in the analysis. We diagnosed small airway dysfunction on the basis of at least two of the following three indicators of lung function being less than 65% of predicted: maximal mid-expiratory flow, forced expiratory flow (FEF) 50%, and FEF 75%. Small airway dysfunction was further categorised into pre-small airway dysfunction (defined as having normal FEV1 and FEV1/forced vital capacity [FVC] ratio before bronchodilator inhalation), and post-small airway dysfunction (defined as having normal FEV1 and FEV1/FVC ratio both before and after bronchodilator inhalation). Logistic regression yielded adjusted odds ratios (ORs) for small airway dysfunction associated with smoking and other lifestyle and environmental factors. We further estimated the total number of cases of small airway dysfunction in China by applying present study findings to national census data. Findings Overall the prevalence of small airway dysfunction was 43·5% (95% CI 40·7–46·3), pre-small airway dysfunction was 25·5% (23·6–27·5), and post-small airway dysfunction was 11·3% (10·3–12·5). After multifactor regression analysis, the risk of small airway dysfunction was significantly associated with age, gender, urbanisation, education level, cigarette smoking, passive smoking, biomass use, exposure to high particulate matter with a diameter less than 2·5 μm (PM2·5) concentrations, history of chronic cough during childhood, history of childhood pneumonia or bronchitis, parental history of respiratory diseases, and increase of body-mass index (BMI) by 5 kg/m2. The ORs for small airway dysfunction and pre-small airway dysfunction were similar, whereas larger effect sizes were generally seen for post-small airway dysfunction than for either small airway dysfunction or pre-small airway dysfunction. For post-small airway dysfunction, cigarette smoking, exposure to PM2·5, and increase of BMI by 5 kg/m2 were significantly associated with increased risk, among preventable risk factors. There was also a dose-response association between cigarette smoking and post-small airway dysfunction among men, but not among women. We estimate that, in 2015, 426 (95% CI 411–468) million adults had small airway dysfunction, 253 (238–278) million had pre-small airway dysfunction, and 111 (104–126) million had post-small airway dysfunction in China. Interpretation In China, spirometry-defined small airway dysfunction is highly prevalent, with cigarette smoking being a major modifiable risk factor, along with PM2·5 exposure and increase of BMI by 5 kg/m2. Our findings emphasise the urgent need to develop and implement effective primary and secondary prevention strategies to reduce the burden of this condition in the general population. Funding Ministry of Science and Technology of China; National Natural Science Foundation of China; National Health Commission of China.

Background and Aims Dynamic hyperinflation (DH) is an important pathophysiological characteristic of chronic obstructive pulmonary disease (COPD). There is increasing evidence that DH has negative effects on exercise performance and quality of life. The objective of this study was to explore effects of DH on exercise capacity and quality of life in stable COPD patients. Methods Fifty-eight COPD patients and 20 matched healthy individuals underwent pulmonary function test, 6-min walk test and symptom-limited cardiopulmonary exercise test (CPET). End-expiratory lung volume/total lung capacity ratio (EELVmax/TLC) at peak exercise of CPET was evaluated, and EELVmax/TLC ≥ 75% was defined as ‘severe dynamic hyperinflation (SDH)’. Results Of the 58 patients studied, 29 (50.0%) presented with SDH (SDH+ group, EELVmax/TLC 79.60 ± 3.60%), having worse maximal exercise capacity reflected by lower peakload, maximal oxygen uptake (VO2max), maximal carbon dioxide output (VCO2max) and maximal minute ventilation (VEmax) than did those without SDH (SDH− group, EELVmax/TLC 67.44 ± 6.53%). The EELVmax/TLC ratio at peak exercise had no association with variables of pulmonary function and 6-min walk distance (6MWD), but correlated inversely with peakload, VO2max, VCO2max and VEmax (r = −0.300~−0.351, P

Background: The evidence for the short-term prognosis of patients with microscopic polyangiitis (MPA) is weak, and the objective of this study was to analyze the clinical features of the disease and evaluate the risk factors for readmission in patients with MPA. Methods: Fifty-seven patients with MPA were recruited into this study. The clinical data of these MPA patients were collected. Clinical manifestations, laboratory results, and imaging results were analyzed. Patients who were readmitted to our hospital within 6 months after their first diagnosis and treatment of MPA were defined as the readmission group; the remaining patients were defined as the control group. Results: Respiratory symptoms, including cough, dyspnea (87.72%), and hemoptysis (3.51%), seemed to be the initial symptoms in many patients with MPA. Systemic symptoms included fever (71.93%), hearing loss (12.28%), vision loss (3.51%), and joint involvement (5.27%). The D-dimer levels of 43 patients (75.44%) were >500 ng/dL, and only three of these patients had venous thrombosis. Age and immunoglobulin A (IgA) were the risk factors for readmission in patients with MPA, with odds ratios (ORs) of 1.162 [95% confidence interval (CI): 1.025–1.317, P=0.019] and 1.010 (95% CI: 1.001–1.018, P=0.028). The days of hospitalization and the a2-globulin level were protective factors with ORs of 0.849 (95% CI: 0.725–0.993 P=0.041) and 0.789 (95% CI: 0.64–0.971, P=0.025), respectively. IgA levels were positively correlated with the number of hospitalizations, with a correlation coefficient of 0.428 (P=0.002). Receiver operating characteristic curve analysis showed that the possibility of readmission increases when the serum levels of IgA were >217.5 mg/dL. Conclusion: The level of serum IgA is a risk factor for the readmission of patients with MPA, and correlated with the number of hospitalizations in these patients.

OBJECTIVE: To elucidate oxygen administration practices in the setting of acute exacerbations of chronic obstructive pulmonary disease (COPD) and compare these practices with those recommended in internationally accepted guidelines. DESIGN: Retrospective audit. PARTICIPANTS AND SETTING: 65 patients admitted to a Melbourne university teaching hospital via the emergency department (ED), identified through medical records by a discharge diagnosis (discharged between 1 June and 30 September 2005) of acute exacerbation of COPD (AECOPD). Those included had respiratory function test results consistent with British Thoracic Society guidelines for the diagnosis of COPD. MAIN OUTCOME MEASURES: Length of stay, need for high dependency unit (HDU) admission, use of non-invasive ventilation (NIV), and use of arterial blood gas (ABG) tests. RESULTS: Our audit showed that 95% of patients defined as retaining carbon dioxide received oxygen at a flow rate greater than 2 L/min. This process began in the ambulance and continued in the ED, often without monitoring of ABG levels. Length of stay was significantly longer (P = 0.029); need for NIV on admission greater (P = 0.0124); and rate of admission to the HDU higher (P = 0.0124) in patients who achieved a partial pressure of arterial oxygen (PaO(2)) >/= 74.5 mmHg compared with those with a PaO(2) < 74.5 mmHg. CONCLUSIONS: The vast majority of patients with AECOPD presenting to our university teaching hospital receive oxygen therapy outside of internationally accepted guidelines, often without monitoring of ABG levels. The use of high-flow oxygen may contribute to an increased length of stay, more frequent admission to HDU and greater use of NIV among patients who achieve a higher PaO(2).