BACKGROUND:Preserved ratio impaired spirometry (PRISm) is regarded as a COPD precursor, but whether this varies by smoking status remains unclear. RESEARCH QUESTION:Are annual lung function decline and the risk of developing airflow limitation different among PRISm subtypes by smoking status? STUDY DESIGN AND METHODS:A total of 2,850 participants from a 15-year population-based prospective cohort were included in this analysis. Participants were categorized into 3 groups: patients with normal spirometry who do not smoke (normal control), patients with PRISm who do not smoke (NS-PRISm), and patients with PRISm who have ever smoked (ES-PRISm). We compared annual lung function decline and the risk of developing airflow limitation among the 3 groups. RESULTS:Participants in the normal control group exhibited the fastest decline in annual lung function, followed by the ES-PRISm group, with the NS-PRISm group showing the slowest decline. Participants in the ES-PRISm group had significantly faster annual lung function decline than the NS-PRISm group. Participants in the ES-PRISm group had a significantly increased risk of developing airflow limitation than the NS-PRISm group (95 of 256 [37.1%] vs 69 of 470 [14.7%]; adjusted hazard ratio [HR], 1.90; 95% CI, 1.31-2.77; P = .001) and normal control group (95 of 256 [37.1%] vs 193 of 2,124 [9.1%]; adjusted HR, 2.69; 95% CI, 1.96-3.69; P < .001). Participants in the NS-PRISm group also exhibited a higher risk of developing airflow limitation than those in the normal control group (69 of 470 [14.7%] vs 193 of 2,124 [9.1%]; adjusted HR, 1.41; 95% CI, 1.07-1.87; P = .016). When the ES-PRISm group was further divided into participants with PRISm who currently smoke and those who formerly smoked, both of these PRISm subtypes showed a faster annual lung function decline and a similarly higher risk of airflow limitation than the NS-PRISm group. INTERPRETATION:These findings suggest that both NS-PRISm and ES-PRISm may be potential precursors to COPD and indicate that PRISm should not be restricted to evaluating individuals with a history of smoking alone.

Small airway dysfunction (SAD) is common but little is known about the longitudinal prognosis of spirometry-defined SAD. Therefore, we aimed to evaluate the risk of lung function decline and incident chronic obstructive pulmonary disease (COPD) of spirometry-defined SAD. It was a population-based prospective cohort study conducted in Guangdong, China. Participants were enrolled in the years 2002, 2008, 2012, 2017, and 2019, and those who completed baseline demographic data, a standardized epidemiological questionnaire for COPD, and spirometry were included. Follow-up visits were conducted every three years after enrolment, with a maximum follow-up time of 15 years and a minimum follow-up time of 3 years. Spirometry-defined SAD was defined as having at least two out of three parameters (maximal mid-expiratory flow, forced expiratory flow 50

Background:Lung cancer combined by chronic obstructive pulmonary disease (LC-COPD) is a common comorbidity and their interaction with each other poses significant clinical challenges. However, there is a lack of well-established consensus on the diagnosis and treatment of LC-COPD. Methods:A panel of experts, comprising specialists in oncology, respiratory medicine, radiology, interventional medicine, and thoracic surgery, was convened. The panel was presented with a comprehensive review of the current evidence pertaining to LC-COPD. After thorough discussions, the panel reached a consensus on 17 recommendations with over 70% agreement in voting to enhance the management of LC-COPD and optimize the care of these patients. Results:The 17 statements focused on pathogenic mechanisms (n=2), general strategies (n=4), and clinical application in COPD (n=2) and lung cancer (n=9) were developed and modified. These statements provide guidance on early screening and treatment selection of LC-COPD, the interplay of lung cancer and COPD on treatment, and considerations during treatment. This consensus also emphasizes patient-centered and personalized treatment in the management of LC-COPD. Conclusions:The consensus highlights the need for concurrent treatment for both lung cancer and COPD in LC-COPD patients, while being mindful of the mutual influence of the two conditions on treatment and monitoring for adverse reactions.

BACKGROUND:Biomass smoke is associated with the risk of chronic obstructive pulmonary disease (COPD), but few studies have elaborated approaches to reduce the risk of COPD from biomass burning. The purpose of this study was to determine whether improved cooking fuels and ventilation have effects on pulmonary function and the incidence of COPD.METHODS AND FINDINGS:A 9-y prospective cohort study was conducted among 996 eligible participants aged at least 40 y from November 1, 2002, through November 30, 2011, in 12 villages in southern China. Interventions were implemented starting in 2002 to improve kitchen ventilation (by providing support and instruction for improving biomass stoves or installing exhaust fans) and to promote the use of clean fuels (i.e., biogas) instead of biomass for cooking (by providing support and instruction for installing household biogas digesters); questionnaire interviews and spirometry tests were performed in 2005, 2008, and 2011. That the interventions improved air quality was confirmed via measurements of indoor air pollutants (i.e., SO₂, CO, CO₂, NO₂, and particulate matter with an aerodynamic diameter of 10 µm or less) in a randomly selected subset of the participants' homes. Annual declines in lung function and COPD incidence were compared between those who took up one, both, or neither of the interventions. Use of clean fuels and improved ventilation were associated with a reduced decline in forced expiratory volume in 1 s (FEV₁): decline in FEV₁ was reduced by 12 ml/y (95% CI, 4 to 20 ml/y) and 13 ml/y (95% CI, 4 to 23 ml/y) in those who used clean fuels and improved ventilation, respectively, compared to those who took up neither intervention, after adjustment for confounders. The combined improvements of use of clean fuels and improved ventilation had the greatest favorable effects on the decline in FEV₁, with a slowing of 16 ml/y (95% CI, 9 to 23 ml/y). The longer the duration of improved fuel use and ventilation, the greater the benefits in slowing the decline of FEV₁ (p<0.05). The reduction in the risk of COPD was unequivocal after the fuel and ventilation improvements, with an odds ratio of 0.28 (95% CI, 0.11 to 0.73) for both improvements.CONCLUSIONS:Replacing biomass with biogas for cooking and improving kitchen ventilation are associated with a reduced decline in FEV₁ and risk of COPD.TRIAL REGISTRATION:Chinese Clinical Trial Register ChiCTR-OCH-12002398.

OBJECTIVE:To investigate the familial aggregation in chronic obstructive pulmonary disease (COPD).METHODS:Based on a cross-sectional survey in seven provinces/cities in China (Beijing, Shanghai, Guangdong, Liaoning, Tianjin, Chongqing and Shaanxi) from 2002 to 2004, the familial aggregation of COPD was investigated with multi-stage cluster random sampling method.One urban and one rural area were selected as samples from each of seven provinces/cities. All residents equal or older than 40 years old received questionnaires and pulmonary function tests. Questionnaires included risk factors of COPD, respiratory symptoms, quality of life, diagnosis and prevention conditions of COPD. Bronchodilator tests, physical examination, X-ray and electrocardiograph (ECG) were conducted in those subjects.In pulmonary function tests, the ratio of the first second forced expiratory volume (FEV1) /forced vital capacity (FVC) less than 70% fulfill the diagnostic criteria of COPD.If any of siblings and parents had chronic bronchitis, emphysema, asthma or COPD, it should be considered as a positive family history of COPD-related disease.Otherwise, it was negative.RESULTS:FEV1 was lower in the subjects with a family history of COPD-related diseases than in those without [(2.24 ± 0.70) L vs (2.28 ± 0.73) L]. The prevalence of COPD in the population with history of COPD-related diseases was 12.1% (540/4 481), which was significantly higher than that without [7.2% (1 128/15 764), χ(2) = 110.599, P < 0.001]. After adjusted for potential confounder, the population with a family history of COPD-related diseases still had much higher incidence of COPD [OR = 2.18 (95%CI 1.94-2.46)]. Furthermore, the population having two or more first-degree relatives with COPD-related diseases, exhibited the highest likelihood of COPD [OR = 2.48 (95%CI 2.00-3.08)]. The population having only one first-degree relative with COPD-related diseases showed an increased risk of COPD with an OR = 2.10 (95%CI 1.84-2.40) compared with those without any one. Those whose father, mother or siblings had COPD-related diseases were similarly likely to have COPD, with an OR of 1.54 (95%CI 1.32-1.80), 1.83 (95%CI 1.56-2.15) and 1.81 (95%CI 1.48-2.23), respectively.CONCLUSIONS:There is a familial aggregation in COPD. The more relatives have COPD-related diseases in the family, the greater risk of COPD the subject will have.

OBJECTIVE:To investigate the prevalence and risk factors of bronchiectasis in urban city of China.METHODS:A cross-sectional survey was conducted in 17 urban areas in Beijing, Shanghai, Tianjin, Chongqing cities, and Guangdong, Liaoning, Shanxi provinces. In this study, urban population-based cluster samples were randomly selected from each city/province. In the selected city communities, all residents at least 40 years old were recruited, interviewed with questionnaires and tested with spirometry. Each participant was asked whether he/she was ever diagnosed as bronchiectasis by physician, whether had symptoms of respiratory diseases and possible risk factors, etc.RESULT:Data of 10 811 participants was enrolled for analysis, with a response rate of 75.4% (10 811/14 337). The overall prevalence of physician-diagnosed bronchiectasis was 1.2% (135/10 811), with 1.5% (65/4382) in male and 1.1% (70/6429) in female, without statistical difference in gender (χ² = 3.289, P = 0.070). Prevalence of bronchiectasis increased with age (χ² = 31.029, P < 0.001). There were no statistical significances in crude prevalences of bronchiectasis among cities (χ² = 10.572, P = 0.103), while there was a significant difference among cities after adjustment with confounders (Wald value = 22.116, P = 0.001), by using logistic regression analysis. Logistic regression analysis showed, bronchiectasis was significantly associated with elder ( ≥ 70 years vs 40-49 years; OR = 4.11, 95% CI 2.29-7.36), the family history of respiratory diseases (having two subjects with respiratory diseases in family vs no suffered relatives; OR = 2.04, 95% CI 1.06-3.94), respiratory infection during childhood (suffering two kinds of respiratory diseases vs never; OR = 4.89, 95% CI 2.03-11.81), exposure to coal (OR = 2.30, 95% CI 1.17-4.52), chronic pharyngitis (OR = 3.96, 95% CI 1.38-11.40) and pulmonary tuberculosis (OR = 3.07, 95% CI 1.89-4.98), heart diseases (OR = 1.64, 95% CI 1.11-2.42) and lung cancer(OR = 18.61, 95% CI 7.67-45.18).CONCLUSION:The prevalence of bronchiectasis in population aged 40 years old and above in urban area in China is high and associated with multiple factors such as age, family history of respiratory diseases, respiratory infection during childhood, exposure to coal, chronic pharyngitis, pulmonary tuberculosis, heart diseases, lung cancer and so on.

OBJECTIVE:To develop a brief, reliable screening questionnaire for chronic obstructive pulmonary disease (COPD) for use in primary care settings.METHODS:We developed a COPD Screening Questionnaire (COPD-SQ) using data collected from 19,800 subjects aged ≥40 years obtained from an epidemiological study of COPD in China in 2002 (Phase I). A stepwise logistic regression method was adopted for item reduction and scoring. We then assessed the COPD-SQ through a cross-sectional study (Phase II) among 3231 subjects aged ≥40 years.RESULTS:The final COPD-SQ consisted of seven items: age, smoking pack-years, body mass index, cough, dyspnoea, family history of respiratory diseases and exposure to biomass smoke from cooking. Using the questionnaire to screen for COPD in Phase II, we obtained high classification accuracy with an area under the curve of 0.812 (95%CI 0.786-0.838). The sensitivity, specificity and correct classification rates for COPD diagnosis were respectively 60.6%, 85.2% and 82.7% at a cut-off score of 16.CONCLUSIONS:The COPD-SQ can be used in first-level screening for COPD.

Background and objective: COPD has a variable natural history and not all individuals follow the same course. The aim of this study was to assess the prevalence of COPD in the absence of chronic bronchitis (CB) based on a population survey in China, and to identify the determinants of CB in patients with COPD.Methods: Amulti-stage cluster sampling strategy was used to survey a population from seven different provinces/cities of China. All residents over 40 years of age were interviewed using a standardized questionnaire and spirometry was measured. A post-bronchodilator FEV1/FVC < 70% was defined as the diagnostic criterion for COPD. All COPD patients who were screened were divided into two groups according to the presence or absence of CB.Results: Of the population of 20 245 that was surveyed, 70% of the 1668 patients who were diagnosed with COPD reported no history of CB. The ages, BMI and comorbidities of COPD patients with or without CB were similar. Male gender, residence in a rural area, having a lower level of education, exposure to tobacco smoke or biomass fuels, poor ventilation in the kitchen and a family history of respiratory disease were all associated with a higher risk of COPD with CB. Patients without CB had less difficulty in walking and higher FEV1/FVC values than patients with CB, but were more likely to be underdiagnosed. The strongest predictors of CB were male gender, current smoking and severity of dyspnoea.Conclusions: This survey confirmed that there is a high prevalence of COPD in the absence of CB in China. It appears that CB is not essential to the diagnosis of COPD.

BACKGROUND:Chronic obstructive pulmonary disease (COPD) has a variable natural history and not all individuals follow the same course. This study aimed to identify the prevalence and characteristics of asymptomatic COPD patients from a population-based survey in China.METHODS:A multistage cluster sampling strategy was used in a population from seven different provinces/cities. All residents (over 40 years old) were interviewed with a standardized questionnaire and spirometry. Post-bronchodilator forced expiratory volume in 1 second (FEV(1))/forced vital capacity (FVC) of less than 70% was defined as the diagnostic criterion of COPD. All COPD patients screened were divided into symptomatic group and asymptomatic group according to the presence or absence of chronic respiratory symptoms. Socio-demographic, personal and exposure variables were collected and analyzed.RESULTS:Among the 1668 patients who were diagnosed with COPD from the 25 627 sampling subjects, 589 (35.3%) were asymptomatic. The age, sex, body mass index (BMI), rural and urban distributions, smoking habit and education levels were similar in the two groups. A total of 64.7% of the asymptomatic patients had no comorbidities. Cardiovascular diseases and lung cancer were more common among symptomatic COPD patients than asymptomatic group. Asymptomatic COPD group were less likely to present with poor ventilation in the kitchen, a family history of respiratory disease and recurrent childhood cough. Asymptomatic COPD patients had significantly higher FEV(1) (73.1% vs. 61.0%), FVC (91.9% vs. 82.0%), and a higher ratio of FEV(1)/FVC (62.9% vs. 58.7%) (all P < 0.001) than symptomatic group. More asymptomatic patients were underdiagnosed (91.9% vs. 54.3%, P < 0.001) than symptomatic patients.CONCLUSIONS:This large population-based survey confirmed a high prevalence of asymptomatic COPD patients in China. More use of spirometry screening test may be important to the early detection of COPD.

Objective To investigate the contribution of occupational exposure to dusts/gases/fumes to chronic obstructive pulmonary disease(COPD) and respiratory symptoms in China.Methods Based on the cross-sectional survey of COPD which was conducted in urban and rural areas of Beijing,Shanghai,Guangdong,Liaoning,Tianjin,Chongqing and Shanxi for residents aged 40 years or older,the association between the occupational exposure to dusts/gases/fumes and COPD and respiratory symptoms was analyzed.The recruited populations were interviewed with questionnaire and were tested with spirometry.The post-bronchodilators FEV1/FVC70% was used as diagnostic criteria of COPD.Having any cough,sputum,wheezing and dyspnea was defined as having respiratory symptoms.Results The prevalence of occupational exposure to dusts/gases/fumes was 20.5%.As shown by multiple-variables Logistic regression analyses,occupational exposure to dusts/fumes/gases [OR=1.20(1.04,1.39)] and dusts of grain [1.48(1.18,1.86)]were associated with COPD;occupational exposure to dusts/fumes/gases [OR=1.37(1.25,1.49)],hard-rock mining [OR=2.31(1.67,3.20)],coal mining [OR=1.71(1.09,2.70)],dusts of cement [OR=1.92(1.47,2.52)],chemical or plastics manufacturing [OR=1.58(1.37,1.83)],spray painting [OR=1.46(1.16,1.84)],and other dusts or fumes [OR=1.46(1.29,1.64)]were associated with the respiratory symptoms.Smoking and occupational exposure to dusts/gases/fumes had synergic effects on the increasing risk of respiratory symptoms.The population-attributable risk(PAR) of exposure to dusts/gases/fumes was 3.94% and 7.05% for COPD and respiratory symptoms respectively.Conclusions Occupational exposure to dusts/gases/fumes is associated with COPD and respiratory symptoms.Smoking and occupational exposure to dusts/gases/fumes may have synergic effects on respiratory symptoms.

OBJECTIVE:To investigate the current status of prevalence, prevention and management of chronic obstructive pulmonary disease (COPD) in rural area in China.METHODS:A cross-sectional survey of COPD was conducted in Beijing city, Shanghai city, Guangdong province, Liaoning province, Tianjin city, Chongqing province and Shanxi province. A population-based cluster sample was randomly selected from each rural area. In the selected community, all residents at least 40 years old were recruited, and interviewed with a modified standardized questionnaire from the international burden of obstructive lung diseases (BOLD) study. All participants were tested with spirometry. Those with airflow limitation were performed on post-bronchodilator spirometry. The post-bronchodilator a ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC) less than 70% was defined as the diagnostic criteria of COPD.RESULTS:(1) Data of 9434 participants was valid for analysis, with a valid response rate of 83.6%; the prevalence of COPD in rural was 8.8% (830/9434), 12.8% in male and 5.4% in female. (2) The percentage of smoking and the exposure to biomass smoke in rural was 43.0% (4059/9434) and 83.1% (7835/9434) respectively; cigarettes cessation rate was 17.5%; only 12.4% (502/4059) of smokers had received advice to quit smoking. (3) Among COPD patients, only 30.0% (249/830) had ever been diagnosed as COPD, bronchitis, emphysema, or asthma, 2.4% (20/830) had ever received spirometric tests, and 74.5% were current smokers; only 7.9% (50/634) COPD patients in stage two or over had received regular drug treatment.CONCLUSION:There was high prevalence and poor prevention and management for COPD in rural areas. Therefore, an enforced prevention and management for COPD are urgent.

OBJECTIVE:To evaluate the quality of life (QOL) of patients with chronic obstructive pulmonary disease (COPD) and correlated factors.METHODS:Data of 20 245 patients with COPD were collected from the cross-sectional survey of COPD, which was conducted between 2002 and 2004 in urban and rural areas of Beijing, Shanghai, Guangdong, Liaoning, Tianjin, Chongqing and Shanxi for residents aged over 40 years old. The recruited populations were interviewed with questionnaire and tested for spirometry. The quality of life was assessed with 12-item short-form health survey questionnaire (SF-12). Those with less than 70% of post-bronchodilator FEV(1)/FVC were identified as having COPD. The differences between groups in SF-12 scores converted by rank were compared using general linear model. Stepwise multiple linear regressions were conducted to study the main determinants of QOL.RESULTS:Compared to subjects without COPD, those with COPD had impaired QOL (56 +/- 7 vs. 57 +/- 6 in mental component scores, F = 4.442, P < 0.05; 46 +/- 9 vs. 50 +/- 6 in physical component scores, F = 453.960, P < 0.05). Among COPD patients, the mental component score was associated with scores of dyspnea, BMI, comorbidities, sex and living areas, while the physical component score was associated with scores of dyspnea, severity of COPD, comorbidities, exposure to dusts/gases/fumes, sex, age, educational level and previous diagnosis of respiratory diseases (all P < 0.05).CONCLUSIONS:The QOL in patients with COPD was impaired and associated with scores of dyspnea, severity of COPD, comorbidities and BMI. Improvement of dyspnea, nutritional support, prevention of comorbidities and keeping away from risk factors may improve the QOL in COPD patients.

OBJECTIVE:To investigate the correlation between body mass index (BMI) and chronic obstructive pulmonary disease (COPD), based on a cross-sectional COPD survey conducted in Beijing, Shanghai, Guangdong, Liaoning, Tianjin, Chongqing and Shaanxi of China between 2002-2004. METHODS:A multi-stage stratification cluster sampling strategy was used in this cross-sectional survey, and 20,245 subjects (8705 males and 11,540 females) aged 40 years or older were recruited, interviewed with a questionnaire, measured for height and weight, and tested with spirometry. 1668 subjects with post-bronchodilator FEV1/FVC less than 70% were identified as having COPD after other known causes of airflow limitation were excluded. Analysis on relationship between COPD and BMI was performed in 1668 COPD and 18 577 non-COPD subjects. RESULTS:Compared with non-COPD subjects, BMI was significantly lower in COPD patients [(22.7+/-3.5) vs (24.1+/-3.4) kg/m2, F=158.31, P<0.01]; BMI was also significantly lower in smokers than in non-smokers [(23.6+/-3.4) vs (24.2+/-3.5) kg/m2, F=49.10, P<0.01]. And an addictive interaction to BMI between COPD and smoking was observed (F=6.03, P<0.05). BMI decreased with the increase of the stage of COPD (F=45.6, P<0.01), with a negative relationship (r=-0.08, P<0.01). Lower BMI was significantly associated with increased risk of COPD (chi2=102.68, P<0.01). Compared with subjects with normal BMI (BMI=24.0-27.9 kg/m2), those with lower BMI (BMI<18.5 kg/m2) were more likely to have COPD [adjusted OR=2.12 (95% CI 1.73-2.59)], while those with higher BMI (BMI=24.0-27.9 kg/m2) and obesity (BMI>or=28.0 kg/m2) were less likely to have COPD [adjusted OR=0.67 (95% CI 0.59-0.76); and 0.60 [(95% CI 0.49-0.73), respectively]. Moreover, there was an interaction to COPD between smoking and BMI (chi2=4.73, P<0.05). Compared with COPD patients with normal BMI, the quality of life in those with lower BMI was impaired (55+/-8 vs 57+/-6 in mental scores of SF-12, F=2.96, P<0.05; 42+/-10 vs 46+/-9 in physical scores of SF-12, F=4.21, P<0.01), and their dyspnea scores were higher (1.4+/-1.5 vs 1.1+/-1.3, chi2=14.32, P<0.01). CONCLUSION:Lower BMI was strongly associated with COPD, possibly as a risk factor for COPD independent of smoking, and a potential predictor for COPD severity.

Background : Increasing evidence show the possible association between chronic obstructive pulmonary disease (COPD) and the use of biomass fuels for cooking and heating in developing countries. Data on COPD prevalence and objective measurement of indoor pollution from biomass fuel has not been widely available from China. Objectives : To investigate the prevalence of COPD in two study communities in Guangdong province in China and measure the association between COPD and indoor biomass fuel air pollution. Methods : A cluster-disproportional-random-sampling survey was performed in populations aged over 40 years in urban (Liwang) and rural (Yunyan) areas in Guangdong, China. Spirometry was performed in all subjects and a post-bronchodilator ratio of the forced expiratory volume in the first second over forced vital capacity of less than 0.70 was defined as COPD. Measurements of indoor and outdoor air pollutants were also performed in a random sample of households. Main Results : The overall prevalence of COPD in the two areas (Liwang and Yunyan) was 9.4%. The prevalence of COPD in both whole population and a subpopulation of non-smoking women in rural Yunyan was significantly higher than that in urban Liwang (12.0% vs 7.4%, and 7.2% vs 2.5% respectively). Biomass fuel use was higher in rural Yunyan than that in urban Liwang (88.1% vs 0.7%). Univariate analysis showed significant association between COPD and exposure to biomass for cooking. Multivariate analysis showed the positive association between COPD and urban/rural area (surrogate for fuel type and local exhaust ventilation in kitchen) after adjustment for gender, age group, BMI, education, occupational exposure, respiratory disease in family, smoking status, life quality and cough in childhood, and similar results were found in non-smoking women. Pollutants measurements showed that CO, PM 10 , SO 2 and NO 2 concentrations in the kitchen during biomass fuel combustion were significantly higher than those during LPG combustion. Conclusion s: Indoor pollutants from biomass fuels may be an important risk factor for COPD in rural South China.

OBJECTIVE To explore the risk factors for chronic obstructive pulmonary disease (COPD) in females in Chinese rural areas. METHODS Based on a national multi-center, population-based and cross-sectional survey on prevalence of COPD in seven provinces/cities of China, an analysis on the risk factors for the rural females was conducted in six areas, e.g. Beijing, Shanghai, Guangdong, Liaoning, Tianjin and Shanxi. In the national survey, for each area, one rural and one urban cluster samples were randomly selected using a multi-stage strategy. Residents who were 40 years old or older were interviewed with questionnaires and tested with spirometry. The post-bronchodilators forced expired volume in one second to forced vital capacity ratio (FEV(1)/FVC) x 100% < 70% was used as diagnostic criteria of COPD. RESULTS The average prevalence of COPD in females in the six Chinese rural areas was 5.4%. The prevalence varied with risk factor exposure among different areas, and the prevalence in Guangdong province was the highest among all areas. Logistic regression model was conducted, and statistical association of COPD was found with a family history of respiratory diseases (OR = 2.46, 95% CI = 1.86 - 3.26), frequent coughing during childhood (frequent coughing vs never coughing: OR = 3.93, 95% CI = 2.02 - 7.63), lower body mass index (lower body mass index vs normal body mass index: OR = 2.20, 95% CI = 1.47 - 3.29), age (70 years or older vs 40 - 49 years: OR = 8.98, 95% CI = 5.90 - 13.67), smoking (OR = 1.68, 95% CI = 1.20 - 2.35), exposure to occupational dusts (OR = 1.45, 95% CI = 1.07 - 1.96), worse ventilation in kitchen room (OR = 1.47, 95% CI = 1.06 - 2.03) and lower educational level (OR = 2.19, 95% CI = 1.38 - 3.46). CONCLUSION The prevalence of COPD in females in rural areas was associated with multiple factors and prevention of COPD for Chinese women in rural areas is warranted.

OBJECTIVE AND BACKGROUND:Increasing evidence suggests that low-dose theophylline has anti-inflammatory benefits and is safe in the treatment of COPD. This study aims to evaluate the efficacy and safety of low-dose, slow-release oral theophylline administered over a 1-year period in patients with COPD. METHODS:A randomized, double-blind, parallel-group, placebo-controlled trial was carried out. In total, 110 participants with COPD were randomly assigned to receive slow-release theophylline (100 mg b.i.d.) or placebo for 1 year. Use of medicine and symptoms recorded by diary cards; pulmonary function, exacerbations of COPD, quality of life and the use of rescue medicine were evaluated. Superiority test was used to estimate the efficacy. RESULTS:Of 110 participants, 85 (77.3%) complied with the protocol, with 42 subjects in theophylline and 43 subjects on placebo. In both intention-to-treat and per-protocol population analysis, greater improvement in pre-bronchodilator FEV(1) (P = 0.038 and P = 0.070, respectively), lower frequency of COPD exacerbations (P = 0.047 and P = 0.035, respectively), fewer days of COPD exacerbations (P = 0.045 and P = 0.046, respectively), lower frequency of clinical visits (P = 0.017 and P = 0.039, respectively), greater improvement in satisfaction with treatment (P = 0.014 and P = 0.004, respectively) were found in the theophylline group than in the placebo group. In per-protocol population, greater improvements in quality of life (P = 0.047) were also observed in the theophylline group and the mean time to the first exacerbation was delayed in theophylline group in comparison with placebo group (P = 0.047). Drug-related adverse events such as stomach discomfort (3.51%), headache (3.51%), insomnia (1.75%) and palpitation (1.75%) were found in the theophylline group. CONCLUSIONS:Low-dose, slow-release oral theophylline is effective and well-tolerated in the long term treatment of stable COPD, although it does not improve post-bronchodilator lung function.

OBJECTIVE To observe the benefits and safety of low-dose, slow-release oral theophylline for long-term treatment of stable chronic obstructive pulmonary disease (COPD). METHODS This was a randomized, parallel-group, double-blind, placebo-controlled trial. Slow-release theophylline (200 mg/d) twice daily or placebo (matching theophylline) was randomly given to 110 patients with stable COPD in the rural area of Shaoguan, Guangdong Province, for one year. Efficacy measures were spirometry and exacerbations, quality of life, dyspnea scores, satisfaction with treatments and adverse effects. Comparison of benefits was performed using superiority test. RESULTS Of 110 patients, 85 (42 subjects in theophylline group and 43 subjects in placebo group) completed the study. An analysis for intention-to-treat (ITT) individuals showed that individuals with the treatment of theophylline experienced statistically fewer numbers [(0.8 +/- 1.2) times/year, (1.7 +/- 2.6) times/year, Z = -1.674, P = 0.047] and days of exacerbations [(4.6 +/- 7.9) d, (12.5 +/- 22.8) d, Z = -1.699, P = 0.045] in comparison to subjects receiving placebo, that patients receiving theophylline were less likely than the placebo group to experience moderate exacerbations [(0.4 +/- 1.0) times/year, (1.0 +/- 1.8) times/year, Z = -2.136, P = 0.017], and that more individuals satisfied with treatments in the theophylline group than the placebo group (n = 16, 3, Z = -2.198, P = 0.014), and that statistically greater improvement in pre-bronchodilators FEV(1) [(0.006 +/- 0.180) L, (-0.053 +/- 0.169) L, t = 1.789, P = 0.038] were found in the theophylline group in comparison to the placebo group. The similar results were observed in an analysis for per-protocol (PP) subjects. Statistical improvement on quality of life was observed in the PP subjects of theophylline group than in placebo group (-28 +/- 20, -20 +/- 23, F = 2.893, P = 0.047). Time to the first exacerbation in patients receiving theophylline was also delayed in comparison to placebo (365 d, 276 d, chi(2) = 3.880, P = 0.049). But no statistical difference was found between the two groups in post-bronchodilators FEV(1) in both ITT and PP subjects (t = -0.012, P = 0.495 and t = 0.040, P = 0.484 respectively). Drug-related adverse events (8.8%) such as insomnia, palpitation, stomach discomforts or stomachache, and headache were observed in the theophylline group. CONCLUSION Slow-released oral theophylline (200 mg/d) may be beneficial and safe in long-term treatment of stable COPD in rural area.

To investigate the prevalence of chronic obstructive pulmonary disease (COPD) and its risk factors in population over 40 years old in northern part of Guangdong province.Using uniform scheme, procedures and questionnaire, a cluster-randomized-sampling survey for the population aged over 40 years in a rural area of Shaoguan in the northern part of Guangdong province was performed. Spirometry was performed for every participant, followed by a bronchodilatation test when bronchial obstruction was present.There were 1468 cases with complete data from 1498 people aged >or= 40 years including 640 males, 828 females with an average age of 54.3 years old. The total prevalence of COPD was 12.0%. The prevalence of COPD in males was significantly higher than that in females (18.3% vs. 7.1%, P < 0.01). Only 80.7% of the patients with COPD presented one or more symptoms as cough, phlegm, or dyspnoea. Underdiagnosis of COPD would be quite serious. Only 26.1% of the cases was previously diagnosed to have chronic bronchitis, emphysema, or COPD. Smoking was an important risk factor to COPD and 78.4% of the patients with COPD were smokers. However, relation of biomass and COPD called for further investigation.Prevalence of COPD was much higher than expected in the northern part of Guangdong while smoking was an most important risk factor of COPD. Lung function test seemed to be of great importance to COPD diagnosis, especially in the earlier period of COPD.

OBJECTIVE:To survey the prevalence of chronic obstructive pulmonary disease (COPD) in urban and rural areas in Guangdong Province and relevant risk factors.METHODS:Using the same protocol including Burden of Obstructive Lung Disease (BOLD) questionnaire, a questionnaire survey was conducted among 3449 respondents, 1370 males and 1916 females, aged over 40 with an average age of 56.8, by random disproportional cluster sampling in Liwang District of Guangzhou City and Yunyan Town, Lechang City, northern Guangdong Province. Spirometry was performed in all subjects. Lung function indices were regarded as gold criteria of diagnosis of COPD.RESULTS:There were 3286 cases with full data and good quality spirometry test, 1370 males and 1916 females, aged 56.8. The total prevalence of COPD was 9.4%. The prevalence of COPD in the males was 15.9%, significantly higher than that in the females (4.8%, P < 0.01). The prevalence in the rural area was 12.0%, significantly higher than that in the urban area (7.4%, chi(2) = 20.3, P < 0.01). 67.7% of the patients with COPD presented symptoms such as cough, expectoration and/or dyspnoea. 58.7% of the COPD patients (78.9% of the male patients and 10.9% of the female patients) smoked. The odd ratio (OR) for COPD in the smokers was 2.59 (95% CI 1.87 - 3.59). Only 15.1% of the smokers (17.9% of the male smokers and 4.1% of the female smokers) developed COPD. No significant relationship was found between pack years of cigarette smoking and COPD prevalence. The risk of COPD was increased when biomass fuels were used in house cooking (OR = 1.54 95% CI 1.08 - 2.20). Furthermore, the combination of biomass fuels and cigarette smoking further increased the risk with the OR of 4.41 (95% CI 3.22 - 6.04), indicating a synergetic impact of smoking and biomass burning on the prevalence of COPD. The Prevalence of doctor-diagnosed COPD based on the clinical manifestation was significant lower than the actual prevalence (only 31.0%).CONCLUSIONS:COPD is a very common disease in Guangdong. The prevalence of COPD is higher in the rural area than in the urban area, which may be attributed to the synergic effect of smoking and biomass burning. Lung function test is of great importance in COPD diagnosis, especially in the earlier stage of COPD and those asymptomatic COPD patients.