Background: Whether individuals with non-obstructive spirometry-defined small airway dysfunction (SAD) have impaired exercise capacity is unclear, particularly in never-smokers. This study clarifies the degree of impaired exercise capacity and its potential cause in individuals with non-obstructive SAD. Methods: This community-based, multiyear cross-sectional study analyzed data collected in Guangdong, China from 2012-2019 by the National Science and Technology Support Plan Program. Measurements of exercise capacity [peak work rate and peak oxygen uptake ((V)over dotO(2peak))] in participants with non-obstructive spirometry-defined SAD (n=157) were compared with those in controls (n=85) and Global Initiative for Chronic Obstructive Lung Disease (GOLD) I patients (n=239). Subgroup analyses were performed by smoking status. Results: The risk of impaired exercise capacity was significantly higher in participants with non-obstructive SAD [(V)over dotO(2peak) <84%predicted, adjusted odds ratio (aOR) =2.53; 95% confidence interval (CI): 1.42-4.52] than in controls but was not significantly different from that in GOLD I patients. Results were consistent within subgroups of smoking status (ever-smokers: non-obstructive SAD vs. controls, aOR =2.44; 95% CI: 1.08-5.51; never-smokers: non-obstructive SAD vs. controls, aOR =2.38, 95% CI: 1.02-5.58). Participants with non-obstructive SAD had a significantly lower peak work rate (beta=-10.5; 95% CI: -16.3 to -4.7) and (V)over dotO(2peak) (%predicted, beta=-4.0; 95% CI: -7.7 to -0.2) and tended to have higher ventilatory equivalents for carbon dioxide at the ventilatory threshold ((V)over dot(E)/(V)over dotCO(2AT), beta=1.1; 95% CI: -0.1 to 2.3) when compared with controls. Both peak work rate and (V)over dot O-2peak were negatively correlated with (V)over dot(E)/(V)over dotCO(2AT). Conclusions: Although not meeting the current criteria for chronic obstructive pulmonary disease, individuals with non-obstructive SAD have impaired exercise capacity that may be associated with ventilatory inefficiency regardless of smoking status.

Objective: To analyse the impaired lung functions of people with biofuel smoke exposure. Methods: Nonsmokers with biofuel smoke exposure were selected as research objects in a mountainous area of northern Guangdong where the families used biofuels as main energies and the nonsmokers without biofuel smoke exposure in the same area as control. Questionnaire interviews and spirometry tests were performed on all subjects. To analyse the differences of lung functions in both. Results: Seventy hundred and seventeen subjects were enro1led in this study.There were 530 nonsmokers with biofuel smoke exposure(observation group) including 442 women and 88 men, average age 54±10. There were 187 nonsmokers without biofuel smoke exposure(control group) including 141 women and 46 men, average age 54±10. There was no significant difference between two groups in age, height, weight, BMI, waist circumference, hip circumference and waist/hip ratio(P>0.05). The pulmonary ventilation function index(FEV(1)%Pred, FEV(1)/FVC) in the observation group was significantly less than that in control group [(100±18) vs.(106±25); (80±10) vs.(83±6) respectively, P<0.05]. Small airway function index(PEF25, PEF50, PEF75, MMPEF and MMPEF%Pred) was significantly less than that in control group(P<0.01). According to the univariate regression analysis and multivariate regression analysis, regression coefficients between BIOFUEL-INDEX and FEV/FVC was -0.1, 95%CI(-0.1, -0.1, P<0.01). According to the threshold analysis, the vertice of BIOFUEL-INDEX was 46.0, where the predicted Y value was 81.76, 95%CI (80.2, 83.33). When BIOFUEL-INDEX<46.0, the regression coefficient was 0, 95%CI (-0.1, 0.0)(P>0.05); when BIOFUEL-INDEX> 46.0, the regression coefficient 2 was -0.1, 95%CI (-0.2, -0.1)(P<0.01). The difference between coefficient 2 and 1 was -0.1, 95%CI (-0.2, 0.0), which was statistically significant (P<0.05). The Log-Likelihood ratio between Model I and Model Ⅱ had statistical significance (P=0.019). Conclusions: The biofuel smokes exposure causes damages in lung function.

OBJECTIVE To investigate the association of-991G﹥A polymorphism in aryl hydrocarbon receptor nuclear translocator(ARNT)gene with susceptibility of chronic obstructive pulmonary disease(COPD).METHODS Polymerase chain reaction-restrained fragment length polymorphism(PCR-RFLP)was applied to detect the-991G﹥A genotypes in 223 COPD patients and 223 healthy controls.SAS 9.13 statistical software was used to analyze the genetic variant and COPD risk through non-conditional Logistic regression.RESULTS Significant differences were found in the distribution of-991G﹥A genotypes of ARNT and allele frequencies between COPD patients and healthy controls(P value was 0.001,0.002 respectively).Compared to the GG genotype,the A(AG+AA)genotypes were associated with increased risk of COPD(adjusted OR=2.01;95% CI=1.30-3.12;P﹤0.001).Further stratification analysis showed that the difference of frequency distributions of-991G﹥A genotypes and alleles were more profound in never smokers.CONCLUSION Our study indicates that the-991G﹥A polymorphism of ARNT gene is associated with increased risk of COPD and the A genotypes may increase the susceptibility of COPD.

Objective To study the effect of cyclopiazonic acid(CPA) on intracellular calcium cation concentration(i) in rat distal pulmonary venous smooth muscle cells(PVSMCs).Methods The primary cultured rat distal PVSMCs were identified by morphology and immunofluorescence.The effects of high potassium(60 mmol/L) and CPA on i in PVSMC were assessed by fluorescence microscopy and InCyte i measurement system.Results Typical growth pattern of vascular smooth cell and positive α-actin staining were observed on the primary cultureof PVSMC.There was significant increase of i in PVSMC in response to high potassium,which could be completely reversed by nifedipine(5 μmol/L).In PVSMC perfused with Ca2+-free Krebs solution containing nifedipine,CPA(10 μmol/L) caused a small transient increase in i.after restoration of extracellular Ca2+ to 2.5 mmol/L,CPA caused marked increases in i.Conclusion CPA increases the i in rat distal PVSMC.CPA induced increase in i may related to Ca2+ release from sarcoplasmic reticulum and the influx of Ca2+ through store-operated Ca2+ channels(SOCC) in PVSMC.

Objective To investigate the current status of knowledge and activity to COPD, providing evidence of targeted intervention on COPD in China.Methods A cross-sectional survey of COPD was conducted in two communities which were sampled from Guangzhou City, using multiple-stage sampling strategy.In the selected community, all residents at least 40 years old were randomly recruited, and interviewed with self-made questionnaire that was tested having a good reliability and validity.Results In the 700 participants, 630 had completed questionnaire with a response rate of 90.0%;only 46.3%(292/630) had a idea of COPD, and 42.2%(266/630) did not known any risk factors of COPD.The percentage of smoking was 40%(252/630), with 75.5%(209/277) in male and 12.2%(43/353) in female, and the prevalence of current smoking was 26.3%(166/630).Among current smokers, 35.0%(59/166)planed to quit smoking.46.0%(290/630)of subjects were exposed to environmental cigarettes smoke.22.4%(141/630) of participants had nothing about smoking harmfulness, and 14.8%(93/630) of them thought it was permitted to smoke in public place.73.3%(462/630)of subjects wanted to received health education, and 93.7%(548/585)liked to get the knowledge of the prevention of COPD.Conclusion Subjects had considerably poor knowledge of prevention and management for COPD in community.Therefore, an enforced prevention and health education for COPD are urgent.

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.

目的:分析广东省湛江地区城乡40岁以上人群慢性阻塞性肺疾病(COPD)的患病现状及危险因素。方法:按城乡分层,在广东省湛江地区以整群随机抽样方法,调查40岁以上居民3051人,采用统一的流行病学调查表格,并进行肺功能检测。结果:(1)2435人完成肺功能检测,应答率79.8%,城市1126人,农村1309人;男939人,女1496人;(2)COPD总患病率为6.0%(145/2435),农村患病率为7.0%(92/1309),显著高于城市的4.7%(53/1126),P<0.05;男性患病率为8.9%(84/939),显著高于女性的4.1%(61/1496),P<0.001。(3)危险因素调查发现,农村的吸烟、吸旱烟、现吸烟、有呼吸病家族史、使用柴草烹饪、有儿童时期呼吸病感染和文化程度低的比例显著高于城市(P<0.05),是农村COPD患病率高于城市的重要原因。结论:COPD正成为重要的疾病负担,应多方位加强COPD的人群防治,尤其在农村。

OBJECTIVETo explore the methodology on prevalence study of chronic obstructive pulmonary disease (COPD) in line with the world, to obtain accurate epidemic data of COPD in China.METHODSA national multi-center cross-sectional survey on prevalence, risk factors and burden of COPD was conducted in China. In each area, a population-based cluster sample of approximately 1450 individuals aged 40 years or older was interviewed, using standardized questionnaires that were revised on the methodology of burden of lung diseases (BOLD) study and according under the context of China. All participants were submitted to pre-bronchodilator spirometry. Those with airflow limitation received post-bronchodilator spirometry, physical examination, X-rays of chest and EKG (electrocardiogram) tests. The post-bronchodialators FEV1/FVC < 70% was identified as having COPD.RESULTSInvestigation has been completed with the same standardized procedures by all sites, up to the requirement of quality control. Over 85.0% of the spirometry tests and 95.0% of questionnaires had met the criteria of quality control in each area. Overall, 95.2% of the data was valid with acceptable spirometry and questionaire, and the valid response rate was 79.0%.CONCLUSIONThe protocol was in line with the international standards, by which the prevalence of COPD in China was of adequate quality and valid.

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.

Aim: To detect the association between the susceptibility of COPD and polymorphism of 38A/G in Clara cells 16 kDa secretory protein(CC16) gene in southern Chinese population of Han nationality.Methods: The 332 subjects with and without COPD were selected from the epidemiologic survey participants with matched-pairs strictly in Guangzhou urban and Shaoguan rural.The genotypes of CC16 gene from the subjects were detected by polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP).Results: No significant differences were observed in the frequencies of polymorphic genotypes in site 38 in exon 1 of CC16 gene between COPD and non-COPD subjects(genotype frequency: AA: 17.5% vs 17.5%;GG: 34.9% vs 42.8%;AG: 47.6% vs 39.7%).The allele frequencies were also not significantly different between two groups(A allele frequency: 41.3% vs 37.3%;G allele frequency: 58.7% vs 62.7%).Conclusion: The genetic polymorphism of 38A/G in CC16 gene might be not associated with the susceptibility to COPD in southern Chinese population of Han nationality.