Heterogeneities and impact profiles of early chronic obstructive pulmonary disease status: findings from the China Pulmonary Health Study.

Background: The prevalence, epidemiological and clinical heterogeneities, and impact profiles of individuals with preserved ratio impaired spirometry (PRISm), pre-COPD, young COPD, and mild COPD in general Chinese population were not known yet. Methods: Data were obtained from the China Pulmonary Health study (2012-2015), a nationally representative cross-sectional survey that recruited 50,991 adults aged 20 years or older. Definitions of the four early disease status were consistent with the latest publications and the Global Initiative for Chronic Obstructive Lung Disease criteria. Findings: The age-standardised prevalences of PRISm, pre-COPD, young COPD, and mild COPD were 5.5% (95% confidence interval, 4.3-6.9), 7.2% (5.9-8.8), 1.1% (0.7-1.8), and 3.1% (2.5-3.8), respectively. In summary, mild COPD was under more direct or established impact factor exposures, such as older age, male gender, lower education level, lower family income, biomass use, air pollution, and more accumulative cigarette exposures; young COPD and pre-COPD experienced more personal and parents' events in earlier lives, such as history of bronchitis or pneumonia in childhood, frequent chronic cough in childhood, parental history of respiratory diseases, passive smoke exposure in childhood, and mother exposed to passive smoke while pregnant; pre-COPD coexisted with heavier symptoms and comorbidities burdens; young COPD exhibited worse airway obstruction; and most of the four early disease status harbored small airway dysfunction. Overall, older age, male gender, lower education level, living in the urban area, occupational exposure, frequent chronic cough in childhood, more accumulated cigarette exposure, comorbid with cardiovascular disease and gastroesophageal reflux disease were all associated with increased presence of the four early COPD status; different impact profiles were additionally observed with distinct entities. Over the four categories, less than 10% had ever taken pulmonary function test; less than 1% reported a previously diagnosed COPD; and no more than 13% had received pharmaceutical treatment. Interpretation: Significant heterogeneities in prevalence, epidemiological and clinical features, and impact profiles were noted under varied defining criteria of early COPD; a unified and validated definition for an early disease stage is warranted. Closer attention, better management, and further research need to be administrated to these population. Funding: Chinese Academy of Medical Sciences Institute of Respiratory Medicine Grant for Young Scholars (No. 2023-ZF-9); China International Medical Foundation (No. Z-2017-24-2301); Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences (No. 2021-I2M-1-049); National High Level Hospital Clinical Research Funding (No. 2022-NHLHCRF-LX-01); Major Program of National Natural Science Foundation of China (No. 82090011).

Mediating Effect of Tobacco Dependence on the Association Between Maternal Smoking During Pregnancy and Chronic Obstructive Pulmonary Disease: Case-Control Study.

BACKGROUND: Maternal smoking during pregnancy (MSDP) is a known risk factor for offspring developing chronic obstructive pulmonary disease (COPD), but the underlying mechanism remains unclear. OBJECTIVE: This study aimed to explore whether the increased COPD risk associated with MSDP could be attributed to tobacco dependence (TD). METHODS: This case-control study used data from the nationwide cross-sectional China Pulmonary Health study, with controls matched for age, sex, and smoking status. TD was defined as smoking within 30 minutes of waking, and the severity of TD was assessed using the Fagerstrom Test for Nicotine Dependence. COPD was diagnosed when the ratio of forced expiratory volume in 1 second to forced vital capacity was <0.7 in a postbronchodilator pulmonary function test according to the 2017 Global Initiative for Chronic Obstructive Lung Disease criteria. Logistic regression was used to examine the correlation between MSDP and COPD, adjusting for age, sex, BMI, educational attainment, place of residence, ethnic background, occupation, childhood passive smoking, residential fine particulate matter, history of childhood pneumonia or bronchitis, average annual household income, and medical history (coronary heart disease, hypertension, and diabetes). Mediation analysis examined TD as a potential mediator in the link between MSDP and COPD risk. The significance of the indirect effect was assessed through 1000 iterations of the "bootstrap" method. RESULTS: The study included 5943 participants (2991 with COPD and 2952 controls). Mothers of the COPD group had higher pregnancy smoking rates (COPD: n=305, 10.20%; controls: n=211, 7.10%; P<.001). TD was more prevalent in the COPD group (COPD: n=582, 40.40%; controls: n=478, 33.90%; P<.001). After adjusting for covariates, MSDP had a significant effect on COPD (ß=.097; P<.001). There was an association between MSDP and TD (ß=.074; P<.001) as well as between TD and COPD (ß=.048; P=.007). Mediation analysis of TD in the MSDP-COPD association showed significant direct and indirect effects (direct: ß=.094; P<.001 and indirect: ß=.004; P=.03). The indirect effect remains present in the smoking population (direct: ß=.120; P<.001 and indirect: ß=.002; P=.03). CONCLUSIONS: This study highlighted the potential association between MSDP and the risk of COPD in offspring, revealing the mediating role of TD in this association. These findings contribute to a deeper understanding of the impact of prenatal tobacco exposure on lung health, laying the groundwork for the development of relevant prevention and treatment strategies.

Prevalence, General and Periodontal Risk Factors of Gastroesophageal Reflux Disease in China.

Purpose: There is insufficient information about the prevalence and risk factors of gastroesophageal reflux disease (GERD) in the Chinese adult population. We aimed to assess the prevalence and identify the risk factors of GERD in China. Methods: We collected data from a nationally representative sample (50,991 subjects) of Chinese adults from a large nation-wide cross-sectional survey. GERD was diagnosed by a standardized Chinese-language GERD questionnaire with a score of ≥ 8. The demographic characteristics, comorbidities and periodontal factors of all participants were collected. Results: Fifty-thousands-one-hundred-eighty-three participants were finally included in this study. The overall prevalence of GERD was 5.6% (95% CI, 5.4-5.8%) among the general Chinese population aged 20 years or older. Women, smokers, and people with older age, BMI ≥ 25.0 kg/m2, urban residence, lower education level or comorbidities were more prevalent with GERD (p < 0.001). Symptoms of severe periodontitis (OR = 1.40, 95% CI 1.28-1.52, p < 0.001) and lower frequency of tooth brushing (OR = 2.01, 95% CI 1.76-2.29, p < 0.001) were significantly associated with risk of GERD. Conclusion: Symptom-based GERD is highly prevalent in the Chinese population. Overweight and smoking are major preventable risk factors for GERD. Periodontal factors are novel potential risk factors for GERD and should be given more attention in GERD prevention.

Chronic Obstructive Pulmonary Disease With Asthma-Like Features in the General Population in China.

Background: Patients with features of both asthma and chronic obstructive pulmonary disease (COPD) are seen commonly in the clinic but less is known in the general population. We investigated the prevalence and the heterogeneity of COPD with concomitant features of asthma in Chinese adult population. Methods: COPD was defined as post-bronchodilator ratio of forced expiratory volume in 1s (FEV1) to forced vital capacity of less than the lower limits of normal. COPD with concomitant features of asthma was defined as either COPD with asthma diagnosed by self-reported physician-diagnosis or by presence of current wheeze, or as COPD with high bronchodilator response (HBR) defined as an increase in FEV1 >15% and >400 ml after bronchodilator. Results: COPD with concomitant features of asthma was found in 1.62% (95% CI 1.31-2.00) of adults (≥20 years) or in 15.2% (95% CI 13.0-17.7) of COPD patients. Compared with COPD with HBR, COPD with asthma diagnosis or wheeze were older (61.8 ± 1.1 years vs. 47.4 ± 2.8 years, P < 0.001), and with a lower post-bronchodilator FEV1%pred (68.2 ± 2.3 vs. 96.6 ± 3.4, P < 0.001). Age, smoking status, biomass use and allergic rhinitis were associated with increasing prevalence of COPD with asthma diagnosis or wheeze, and had greater impaired health status, more comorbidities and more acute exacerbations in the preceding 12 months. Conclusions: COPD with concomitant features of asthma is common in people with COPD and those with COPD with asthma diagnosis or wheeze experience worse clinical severity than COPD with HBR. These findings will help toward the definition of the asthma-COPD overlap condition.

Development and Validation of a Screening Questionnaire of COPD from a Large Epidemiological Study in China.

OBJECTIVE: We aimed to establish an easy-to-use screening questionnaire with risk factors and suspected symptoms of COPD for primary health care settings. METHODS: Based on a nationwide epidemiological study of pulmonary health among adults in mainland China (China Pulmonary Health, CPH study) between 2012 and 2015, participants ≥40 years who completed the questionnaire and spirometry tests were recruited and randomly divided into development set and validation set by the ratio of 2:1. Parameters including sex, age, BMI, residence, education, smoking status, smoking pack-years, biomass exposure, parental history of respiratory diseases and daily respiratory symptoms were initially selected for the development of scoring system. Receiver operating characteristic (ROC) curve, area under curve (AUC), positive and negative predictive values were calculated in development set and validation set. RESULTS: After random split by 2:1 ratio, 22443 individuals were assigned to development set and 11221 to validation set. Ten variables were significantly associated with COPD independently in development set after a stepwise selection by multivariable logistic model and used to develop scoring system. The scoring system yielded good discrimination, as measured by AUC of 0.7737, and in the validation set, the AUC was 0.7711. When applying a cutoff point of ≥16, the sensitivity in development set was 0.69 (0.67 - 0.71); specificity 0.72 (0.71 - 0.73), PPV 0.25 (0.24 - 0.26) and NPV 0.94 (0.94 - 0.95). CONCLUSION: We developed and validated a comprehensive screening questionnaire, COPD-CPHS, with good discrimination. The score system still needs to be validated by large cohort in the future.Supplemental data for this article is available online at https://doi.org/10.1080/15412555.2022.2042504 .

Associations of residential greenness with lung function and chronic obstructive pulmonary disease in China.

BACKGROUND: Studies on the association of greenness with respiratory health are scarce in developing countries, and previous studies in China have focused on only one or two indicators of lung function. OBJECTIVE: The study aims to evaluate the associations of residential greenness with full-spectrum lung function indicators and prevalence of chronic obstructive pulmonary disease (COPD). METHODS: This nationwide cross-sectional survey included 50,991 participants from the China Pulmonary Health study. Lung function indicators included four categories: indicators of obstructive ventilatory dysfunction (FEV1, FVC and FEV1/FVC); an indicator of large-airway dysfunction (PEF); indicators of small-airway dysfunction (FEF25-75% and FEV3/FEV6); and other indicators. Residential greenness was assessed by the Normalized Difference Vegetation Index (NDVI). Multivariable linear regression models and logistic regression models were used to analyze associations of greenness with lung function and COPD prevalence. RESULTS: Within the 500 m buffer, an interquartile range (IQR) increase in NDVI was associated with higher FEV1 (24.76 mL), FVC (16.52 mL), FEV1/FVC (0.38), FEF50% (56.34 mL/s), FEF75% (33.43 mL/s), FEF25-75% (60.73 mL/s), FEV3 (18.59 mL), and FEV6 (21.85 mL). However, NDVI was associated with lower PEF. In addition, NDVI was significantly associated with 10% lower odds of COPD. The stratified analyses found that the associations were only significant in middle-young people, females, and nonsmokers. The associations were influenced by geographic regions. CONCLUSIONS: Residential greenness was associated with better lung function and lower odds of COPD in China. These findings provide a scientific basis for healthy community planning.

Association of fine particulate matter air pollution and its constituents with lung function: The China Pulmonary Health study.

The associations of long-term exposure to various constituents of fine particulate matter (≤2.5 µm in aerodynamic diameter, PM2.5) air pollution with lung function were not clearly elucidated in developing countries. The aim was to evaluate the associations of long-term exposure to main constituents of PM2.5 with lung function in China. This is a nationwide, cross-sectional analysis among 50,991 study participants from the China Pulmonary Health study. Multivariable linear regression models were used to obtain differences of forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), FEV1/FVC, peak expiratory flow (PEF), and forced expiratory flow at 25-75% of exhaled FVC (FEF25-75%) associated with an interquartile range (IQR) change of PM2.5 or its constituents. Residential annual PM2.5 levels varied from 26 µg/m3 to 92 µg/m3 (average: 53 µg/m3). An IQR increase of PM2.5 concentrations was associated with lower FEV1 (19.82 mL, 95% CI: 11.30-28.33), FVC (17.45 mL, 95% CI: 7.16-27.74), PEF (86.64 mL/s, 95% CI: 59.77-113.52), and FEF25-75% (31.93 mL/s, 95% CI: 16.64-47.22). Black carbon, organic matter, ammonium, sulfate, and nitrate were negatively associated with most lung function indicators, with organic matter and nitrate showing consistently larger magnitude of associations than PM2.5 mass. This large-scale study provides first-hand epidemiological evidence that long-term exposure to ambient PM2.5 and some constituents, especially organic matter and nitrate, were associated with lower large- and small- airway function.

Prevalence and risk factors of small airway dysfunction, and association with smoking, in China: findings from a national cross-sectional study.

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.

Prevalence, risk factors, and management of asthma in China: a national cross-sectional study.

BACKGROUND: Asthma is a common chronic airway disease worldwide. Despite its large population size, China has had no comprehensive study of the national prevalence, risk factors, and management of asthma. We therefore aimed to estimate the national prevalence of asthma in a representative sample of the Chinese population. METHODS: A representative sample of 57 779 adults aged 20 years or older was recruited for the national cross-sectional China Pulmonary Health (CPH) study using a multi-stage stratified sampling method with parameters derived from the 2010 census. Ten Chinese provinces, representative of all socioeconomic settings, from six geographical regions were selected, and all assessments were done in local health centres. Exclusion criteria were temporary residence, inability to take a spirometry test, hospital treatment of cardiovascular conditions or tuberculosis, and pregnancy and breastfeeding. Asthma was determined on the basis of a self-reported history of diagnosis by a physician or by wheezing symptoms in the preceding 12 months. All participants were assessed with a standard asthma questionnaire and were classed as having or not having airflow limitation through pulmonary function tests before and after the use of a bronchodilator (400 µg of salbutamol). Risk factors for asthma were examined by multivariable-adjusted analyses done in all participants for whom data on the variables of interest were available. Disease management was assessed by the self-reported history of physician diagnosis, treatments, and hospital visits in people with asthma. FINDINGS: Between June 22, 2012, and May 25, 2015, 57 779 participants were recruited into the CPH study. 50 991 (21 446 men and 29 545 women) completed the questionnaire survey and had reliable post-bronchodilator pulmonary function test results and were thus included in the final analysis. The overall prevalence of asthma in our sample was 4·2% (95% CI 3·1-5·6), representing 45·7 million Chinese adults. The prevalence of asthma with airflow limitation was 1·1% (0·9-1·4), representing 13·1 million adults. Cigarette smoking (odds ratio [OR] 1·89, 95% CI 1·26-2·84; p=0·004), allergic rhinitis (3·06, 2·26-4·15; p<0·0001), childhood pneumonia or bronchitis (2·43, 1·44-4·10; p=0·002), parental history of respiratory disease (1·44, 1·02-2·04; p=0·040), and low education attainment (p=0·045) were associated with prevalent asthma. In 2032 people with asthma, only 28·8% (95% CI 19·7-40·0) reported ever being diagnosed by a physician, 23·4% (13·9-36·6) had a previous pulmonary function test, and 5·6% (3·1-9·9) had been treated with inhaled corticosteroids. Furthermore, 15·5% (11·4-20·8) people with asthma reported at least one emergency room visit and 7·2% (4·9-10·5) at least one hospital admission due to exacerbation of respiratory symptoms within the preceding year. INTERPRETATION: Asthma is prevalent but largely undiagnosed and undertreated in China. It is crucial to increase the awareness of asthma and disseminate standardised treatment in clinical settings to reduce the disease burden. FUNDING: National Key R&D Program of China, Ministry of Science and Technology of China; the Special Research Foundation for Public Welfare of Health, Ministry of Health of China; the Chinese National Research Program for Key Issues in Air Pollution Control; and the National Natural Science Foundation of China.

Periodontal health: A national cross-sectional study of knowledge, attitudes and practices for the public oral health strategy in China.

AIM: To assess the status of periodontal health knowledge, attitudes and practices (KAP) among Chinese adults. MATERIALS AND METHODS: A cross-sectional study was conducted in a nationally representative sample of adults (N = 50,991) aged 20 years or older from ten provinces, autonomous regions, and municipalities. Percentages of Chinese adults with correct periodontal knowledge, positive periodontal attitudes, and practices were estimated. Multiple logistic regression analyses were used to examine the related factors. RESULTS: Less than 20% of Chinese adults were knowledgeable about periodontal disease. Very few (2.6%) of Chinese adults use dental floss ≥once a day and undergo scaling ≥once a year and visit a dentist (6.4%) in the case of gingival bleeding. Periodontal health KAP was associated with gender, age, body mass index, marital status, place of residence, education level, income, smoking status, and history of periodontal disease. CONCLUSIONS: Periodontal health KAP are generally poor among the Chinese adult population. Community-based health strategies to improve periodontal health KAP need to be implemented. Increasing knowledge of periodontal disease, the cultivation of correct practices in response to gingival bleeding, and the development of good habits concerning the use of dental floss and regular scaling should be public oral health priorities.

Prevalence and risk factors of chronic obstructive pulmonary disease in China (the China Pulmonary Health [CPH] study): a national cross-sectional study.

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<0·0001 for sex difference) and in people aged 40 years or older (13·7%, 12·1-15·5) than in those aged 20-39 years (2·1%, 1·4-3·2; p<0·0001 for age difference). Only 12·0% (95% CI 8·1-17·4) of people with COPD reported a previous pulmonary function test. Risk factors for COPD included smoking exposure of 20 pack-years or more (odds ratio [OR] 1·95, 95% CI 1·53-2·47), exposure to annual mean particulate matter with a diameter less than 2·5 µm of 50-74 µg/m3 (1·85, 1·23-2·77) or 75 µg/m3 or higher (2·00, 1·36-2·92), underweight (body-mass index <18·5 kg/m2; 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.

Recurrent bilateral spontaneous pneumothorax secondary to lung adenocarcinoma with epidermal growth factor receptor mutation.

A 42-year-old female patient was admitted for recurrent bilateral spontaneous pneumothorax. High resolution computed tomography showed bilateral pneumothorax and numerous round and oval, thin-walled lung cysts. Microscopically, each small cyst was composed of distended subpleural alveolar spaces. Tumor cells, characteristic of acinar adenocarcinoma, obstructed and narrowed the terminal bronchioles. There was no tumor necrosis or mucin production. This suggested check-valve as a possible mechanism of the thin-walled cysts and pneumothorax. Genetic analysis suggested that the tumors were positive for epidermal growth factor receptor mutation L858R in exon 21. Bilateral spontaneous pneumothorax and thin-walled cysts in association with lung cancer is rarely reported and may be confused with cystic benign lung lesions.

Characteristics of stable chronic obstructive pulmonary disease patients in the pulmonology clinics of seven Asian cities.

BACKGROUND AND OBJECTIVES: Chronic obstructive pulmonary disease (COPD) is responsible for significant morbidity and mortality worldwide. We evaluated the characteristics of stable COPD patients in the pulmonology clinics of seven Asian cities and also evaluated whether the exposure to biomass fuels and dusty jobs were related to respiratory symptoms, airflow limitation, and quality of life in the COPD patients. METHODS: This cross-sectional observational study recruited 922 COPD patients from seven cities of Asia. The patients underwent spirometry and were administered questionnaires about their exposure to cigarette smoking, biomass fuels, and dusty jobs in addition to respiratory symptoms and health related quality of life. RESULTS: Of the patients, there appeared to be variations from city to city in the history of exposure to biomass fuels and dusty jobs and also in respiratory symptoms of cough, phlegm, wheeze, and dyspnea. These symptoms were more frequent in those COPD patients with a history of exposure to biomass fuels than without and those with a history of exposure to dusty jobs than without (P < 0.01 for all comparisons). Airflow limitation was more severe in those COPD patients with a history of exposure to biomass fuels than without (52.2% predicted versus 55.9% of post-bronchodilator forced expiratory volume in 1 second [FEV(1)], P = 0.009); quality of life was poorer in those with exposure to biomass fuels than without (40.4 versus 36.2 of the St George's Respiratory Questionnaire [SGRQ] total score, P = 0.001). Airflow limitation was more severe in those COPD patients with a history of exposure to dusty jobs than without (51.2% predicted versus 57.3% of post-bronchodilator FEV(1), P < 0.001); quality of life was poorer in those with dusty jobs than without (41.0 versus 34.6 of SGRQ score, P = 0.006). CONCLUSION: In Asian cities, the characteristics of COPD patients vary and the history of exposure to biomass fuels or dusty jobs was related to frequency of symptoms, severe airflow limitation, and poor quality of life.

The cross-sectional and longitudinal association of the BODE index with quality of life in patients with chronic obstructive pulmonary disease.

BACKGROUND: The body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index was shown at predicting the risk of death, exacerbation and disease severity among patients with COPD, but few studies verified relationship between BODE index and health related quality of life (HRQoL) among Chinese COPD patients. The objective of this study was to evaluate the relationship between BODE index and HRQoL in cross-sectional and longitudinal association analyses. METHODS: A multi-center prospective cohort study was initially conducted in 491 stable COPD patients in Beijing, China. Health status (HRQoL) was assessed by St. George's Respiratory Questionnaire (SGRQ); the BODE index was calculated for each patient; dyspnea was assessed using the 5-grade Medical Research Council dyspnea scale. Other measurements included socio-demographic, body mass index (BMI), lung function test and 6-minute-walk test (6MWT). Patients were then followed monthly for 12 months. RESULTS: Only 450 patients completed the 1-year follow up and were enrolled in our present analyses. Mean age was (65.2 +/- 10.6) years, men 309 (68.7%). The BODE index was categorized into 4 subgroups: 0 - 2, 3 - 4, 5 - 6 and 7 - 10. At baseline BODE index was gradually increased with baseline total SGRQ and SGRQ subscales (P trend < 0.001). For individual components of BODE index, with the decrease of airflow limitation, and 6MWD, and with the increase of Medical Research Council (MRC) dyspnea grade, total SGRQ and SGRQ subscales were increased correspondingly, P trend < 0.05, respectively. Similar association patterns were found between baseline BODE index and its individual components and mean SGRQ scores at the end of 1-year follow up. By multiple linear regression analyses, baseline BODE index was not only significantly associated with SGRQ score at baseline but also with SGRQ score at the end of 1-year follow up after adjustment for age, male, current smoking, betas being 0.434 and 0.378, respectively. CONCLUSIONS: BODE index is associated with SGRQ score cross-sectionally and longitudinally among stable COPD patients. BODE index might have potential to be used as a sensitive tool to assess the status of quality of life and to monitor disease progression among stable COPD patients.