Risk factors and intervention for chronic obstructive pulmonary disease in China

Prevalence of non-smoking chronic obstructive pulmonary disease and its risk factors in China: a systematic review and meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a prevalent chronic disorder in China, impacting a significant proportion of individuals aged > 40 years. In China, the prevalence of and risk factors for COPD among non-smokers remain largely unexplored. In this study, we aimed to determine the prevalence of COPD in non-smokers within the Chinese population and identify potential risk factors associated with COPD in non-smokers.

METHODS

Web of Science, PubMed, Embase, Chinese WanFang, Chinese China National Knowledge Infrastructure, and Weipu databases from inception to August 5, 2024, were searched. Studies reporting the percentage of never-smokers among those diagnosed with COPD and investigations exploring the risk factors associated with COPD in never-smokers in China were examined. Summary proportions and odds ratios (OR), along with their corresponding 95% confidence intervals (95% CI), were measured.

RESULTS

In total, 112 investigations with 491,812 participants were included. The percentage of never-smokers in people with COPD was 41.1% (95% CI: 37.5-44.6%). The prevalence of never-smokers among males diagnosed with COPD was 22.3% (95% CI: 18.8-25.7%), which differed from that among women (81.3%, 95% CI: 75.3-87.2%). The results showed an association between the utilization of biomass fuel and the occurrence of COPD in never-smokers (OR: 1.25, 95% CI: 1.06-1.44). Among never-smokers, the data showed a close association between being underweight (OR: 1.89, 95% CI: 1.78-2.00), tuberculosis history (OR: 1.71, 95% CI: 1.53-1.88) and COPD. Never-smokers living in rural areas or those with low educational status were more susceptible to COPD.

CONCLUSION

This review confirmed the highly different proportions of never-smokers among male and female patients with COPD.

TRIAL REGISTRATION

PROSPERO: CRD42023420786.

Genetic screening of MMP1 as a potential pathogenic gene in chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a complex and heterogeneous syndrome. Airway inflammation and remodeling are the two key processes involved in COPD pathogenesis. However, the key pathogenic genes driving COPD development have not been revealed. This study aims to identify and validate hub gene(s) underlying COPD development through bioinformatics analysis and experimental validation.

METHODS

Three lung tissue sequencing datasets of the COPD (including GSE38974, GSE103174, and GSE106986) were analyzed. Further, differentially expressed genes (DEGs) were used to compare patients with COPD with non-COPD individuals, and the Robust Rank Aggregation (RRA) analysis was also performed. Results revealed a series of potential pathogenic genes of COPD. DEGs were subjected to KEGG, GO, and GSEA analyses. The scRNA dataset of human lung tissues (Human Lung Cell Atlas), and human primary airway epithelial cells (GSE134147) were used to identify the cell subtype localization. The qRT-PCR assay was performed in the human lung tissues, COPD mice model, and primary bronchial epithelial cells at the air-liquid interface (ALI) under cigarette smoke extract (CSE) stimulation to verify the expression of the hub genes. LASSO and GLM analysis with the hub genes were performed to identify the most critical gene. RNA-seq was performed after knocking down the critical gene using siRNA in HBECs at ALI. The potential role of the critical gene was confirmed through qRT-PCR, Western blot, and Immunofluorescence (IF) assays.

RESULTS

A total of 98 genes were significantly and differently expressed in 3 GEO datasets. The KEGG and GO analyses showed that most of these genes are responsible for inflammation, immunity, and cell proliferation. The core gene set including 15 genes was screened out and consequently, the MMP1 was the most likely responsible for the progression of COPD. Moreover, we confirmed that MMP1 is significantly related to inflammatory effects and cilia function in human bronchial epithelial cells cultured at the air-liquid interface (ALI).

CONCLUSION

In summary, we confirmed that inflammation and cell proliferation are potentially critical processes in COPD occurrence and development. A total of 15 potential hub genes were identified among which MMP1 was the most likely gene responsible for the development of COPD. Therefore, MMP1 is a potential molecular target of COPD therapy.

Regional differences in the contribution of smoking, dietary and cooking behaviours to airflow obstruction in China: A population-based case-control study

BACKGROUND AND OBJECTIVE

The major contributing risk factors to airflow obstruction (AO) in China remain largely unknown. We examined the environmental and lifestyle risk factors of unrecognized AO in the baseline of a population-based cohort drawn from 115 urban and rural communities across 12 provinces in China.

METHODS

Amongst 46,285 adults recruited from 2005 to 2009, 3686 were identified with AO on spirometry (defined by the ratio of forced expiratory volume in the first second to forced vital capacity <0.7) and without known chronic lung disease. These cases were age- and sex-matched to 11,129 controls with normal spirometry and no chronic lung disease from the same community. Conditional multivariable adjusted OR and population attributable fraction (PAF) were calculated for each identified risk factor and their combined effect.

RESULTS

Compared to controls, smoking initiation age <20 years (OR 1.22 [95% CI 1.01-1.48]), smoking duration ≥40 years (OR 1.82 [1.50-2.22]), low vegetables (OR 1.86 [1.67-2.07]) and fruits (OR 1.14 [1.02-1.29]) intake, cooking with biomass fuels (OR 2.54 [2.32-2.78]) and poor kitchen ventilation (OR 1.37 [1.19-1.58]) were significantly associated with elevated risks of unrecognized AO. The combined effect of these lifestyle factors significantly elevated the odds by 25 fold (18.6-34.3). The addition of prior tuberculosis and low socioeconomic status further increased the odds to 40.1 (28.2-57.0) and the PAF to 66.7% (51.1-78.1).

CONCLUSION

Smoking, unhealthy diet, biomass cooking fuels and low socioeconomic status are strongly associated with AO. Addressing these risk factors could substantially reduce the burden of AO in China.

Global disease burden of COPD from 1990 to 2019 and prediction of future disease burden trend in China

OBJECTIVES

This study aimed to assess and predict the disease burden attributable to chronic obstructive pulmonary disease (COPD) in a timely, comprehensive, and reliable manner, thereby mitigating the health hazards of COPD.

STUDY DESIGN AND METHODS

Data on the disease burden owing to COPD from 1990 to 2019 were extracted from the Global Burden of Disease (GBD) Study 2019. Linear regression analysis was used to calculate the estimated annual percentage change (EAPC) in the age-standardized rates. Non-parametric tests were used for subgroup analysis. The Bayesian age-period-cohot (BAPC) model integrated nested Laplace approximations to predict the disease burden over the next 25 years. Sensitivity analysis was performed using the Norpred APC model.

RESULTS

Globally, the COPD-related age-standardized incidence rate decreased from 216.48/100,000 in 1990 to 200.49/100,000 in 2019, with an EAPC of -0.33. But the number of new cases increased from 8,722,966 in 1990 to 16, 214, 828 in 2019. Trends in prevalence, deaths, and disability-adjusted life years (DALYs) were the same as incidence. There were significant differences in disease burden between the genders and all age groups (P < 0.05) in China. The projections suggested that the COPD-related number of new cases and deaths in China would increase by approximately 1.5 times over the next 25 years.

CONCLUSIONS

The number of incidence, prevalence, deaths, and DALYs had all increased in China in the past and would continue to grow over the next 25 years. Therefore, measures should be taken to target risk factors and high-risk groups.

Associations of air pollutants with pneumonia hospital admissions in Qingdao, China: a prospective cohort study

Studies about the pneumonia morbidity effects of various air pollution exposure are still limited in China. We aimed to explore the short-term effect of air pollutants exposure on pneumonia admission and identify the vulnerable groups in Qingdao, China. From January 2015 to October 2017, a prospective cohort involving 433,032 participants across 3 counties in Qingdao were enrolled in the study. Distributed lag nonlinear model (DLNM) was applied to assess the associations between air pollutants and pneumonia hospitalizations. There were 636 cases of pneumonia, with an annual incidence density of 54.33 per 100,000 person-years (95% CI: 50.11, 58.56). A 10 μg/m³ increment of sulfur dioxide (SO₂) distributed at a 4-week lag in Qingdao was associated with increased pneumonia hospitalizations, with a risk ratio of 2.10 (95% CI: 1.06, 4.13). Subgroup analyses indicate that PM ≤ 2.5 μm in aerodynamic diameter and SO₂ showed stronger effects on pneumonia in females than males, whereas people in urban regions were more vulnerable to nitrogen dioxide and ozone (O₃) than the others. We also observed distinct acute effects and harvesting effects of SO₂ and O₃ on pneumonia in urban areas. Strategies should be taken to further reduce levels of ambient PM_2.5, SO₂, and O₃.

8-Hydroxyquinolin-2(1H)-one analogues as potential β2-agonists: Design, synthesis and activity study

β₂-Agonists that bind to plasmalemmal β₂-adrenoceptors causing cAMP accumulation are widely used as bronchodilators in chronic respiratory diseases. Here, we designed and synthesized a group of 8-hydroxyquinolin-2(1H)-one analogues and studied their β₂-agonistic activities with a cellular cAMP assay. Compounds B05 and C08 were identified as potent (EC₅₀ < 20 pM) and selective β₂-agonists among the compounds tested. They behaved as partial β₂-agonists in non-overexpressed HEK293 cells, and possessed rapid smooth muscle relaxant actions and long duration of action in isolated guinea pig tracheal strip preparations. In summary, B05 and C08 are β₂-agonists with potential applicability in chronic respiratory diseases.

Functional variations of the TLR4 gene in association with chronic obstructive pulmonary disease and pulmonary tuberculosis

Objective

Chronic obstructive pulmonary disease (COPD) and pulmonary tuberculosis (PTB) share a number of common risk factors, including innate immunity-related genetic factors. In the present study, we compared the role of genetic variations of the TLR4 gene in susceptibility to COPD and PTB and illuminated the underlying molecular mechanism of functional single-nucleotide polymorphisms (SNPs).

Methods

A population-based case control study was performed in a Chinese Han population and included 152 COPD cases, 1601 PTB cases and 1727 controls. Five SNPs in the TLR4 gene (rs10759932, rs2737190, rs7873784, rs11536889, and rs10983755) were genotyped using TaqMan allelic discrimination technology. We estimated the effects of SNPs using the odds ratio (OR) together with 95% confidence interval (CI). Dual-luciferase reporter vectors expressing different genotypes of SNPs were constructed and transfected into the human HEK 293 T cell line to explore their effects on potential transcription activity.

Results

After Bonferroni correction, the genetic polymorphisms of all five SNPs remained significantly associated with COPD, while rs10759932 and rs2737190 were also associated with PTB. Compared with rs10759932-TT, individuals carrying TC (OR: 0.42, 95% CI: 0.28–0.64) or CC (OR: 0.24, 95% CI: 0.09–0.63) had a significantly reduced risk of COPD. However, individuals carrying TC (OR: 1.28, 95% CI: 1.11–1.49) or CC (OR: 1.26, 95% CI: 0.98–1.62) had an increased risk of PTB. The OR (95% CI) for allele rs10759932-C was 0.45 (0.32–0.62) for COPD and 1.18 (1.07–1.32) for PTB. For rs2737190, heterozygous AG was related to a decreased risk of COPD (OR: 0.32, 95% CI: 0.21–0.49) and an increased risk of PTB (OR: 1.30, 95% CI: 1.11–1.52). The dual-luciferase reporter assay showed decreased transcription activity caused by rs10759932-C and rs2737190-G.

Conclusion

Genetic polymorphisms of rs10759932 and rs2737190 in TLR4 are significantly related to both COPD and PTB but with inverse effects. The altered transcription activity caused by mutations in these two loci may partly explain the observed relationship.

Association among genetic polymorphisms of GSTP1, HO-1, and SOD-3 and chronic obstructive pulmonary disease susceptibility

Background

Chronic obstructive pulmonary disease (COPD) is a progressive lung disease characterized by incomplete reversible airflow limitation, which is associated with emphysema and chronic inflammation. Oxidative/antioxidant imbalance is one of the mechanisms of the current pathogenesis of COPD and several recent studies have attempted to uncover genetic causes of COPD and its progression. GST, HO-1, and SOD-3 are important susceptibility genes related to COPD.

Methods

A total of 300 blood samples were included in two groups: Control group and COPD group. We genotyped 4 single nucleotide polymorphisms (SNPs) from these 3 genes in 150 COPD patients and 150 controls to analyze genetic polymorphisms and interactions with COPD-related quantitative traits using correlation analysis and multivariate logistic regression analysis.

Results

The results indicated that genotype distributions and allele frequencies of GSTP1, HO-1, and SOD-3 were significantly different between the COPD and the control group, while there is no correlation between the polymorphism of GSTP1, HO-1, SOD3, and the different stages of COPD. Furthermore, multivariate logistic regression analysis indicated that COPD GSTP1-exon5 SNP and HO-1 (GT)n SNP are high-risk factors for COPD and there was interaction between GSTP1 exon5 SNPS and HO-1 (GT)n SNP. More important, the genotypes, AG, GG of GSTP1 exon5 and L/M*S, L/L of HO-1 (GT)n associated with increased 8-iso-prostaglandin F (2 alpha) (8-iso-PGF2) and malondialdehyde (MDA) concentration and decreased catalase (CAT) activity.

Conclusion

Collectively, this study shows that genetic polymorphisms of GSTP1, HO-1, and SOD-3 are associated with COPD susceptibility.

Effect of physical therapy for chronic obstructive pulmonary disease: A protocol for an updated systematic review of randomized controlled trial

BACKGROUND

Previous studies have reported that physical therapy (PT) can be used for the treatment of chronic obstructive pulmonary disease (COPD). However, its effectiveness is still inconclusive. This systematic review will aim to assess its effectiveness and safety for the treatment of patients with COPD.

METHODS

All randomized controlled trials (RCTs) literatures of PT for COPD will be searched from the databases of Cochrane Central Register of Controlled Trials (CENTRAL), EMBASE, MEDILINE, Web of Science, Cumulative Index to Nursing and Allied Health Literature, Allied and Complementary Medicine Database, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, VIP Information, and Wanfang Data from inception to the present without any language restrictions. Two reviewers will independently perform the study selection, data extraction, and methodological quality assessment. A third reviewer will be invited to resolve any disagreements occurred between 2 reviewers.

RESULTS

The primary outcome is lung function. The secondary outcomes include symptoms, health-related quality of life, mortality, and adverse events. The outcome data will be pooled by using the models of random-effects or fixed-effects according to the detected heterogeneity.

CONCLUSION

The findings of this study will provide up-todated summary evidence for assessing the effectiveness and safety of PT for COPD.

Targeted Treatments for Chronic Obstructive Pulmonary Disease (COPD) Using Low-Molecular-Weight Drugs (LMWDs)

Chronic obstructive pulmonary disease (COPD) is a very common and frequently fatal airway disease. Current therapies for COPD depend mainly on long-acting bronchodilators, which cannot target the pathogenic mechanisms of chronic inflammation in COPD. New pharmaceutical therapies for the inflammatory processes of COPD are urgently needed. Several anti-inflammatory targets have been identified based on increased understanding of the pathogenesis of COPD, which raises new hopes for targeted treatment of this fatal respiratory disease. In this review, we discuss the recent advances in bioactive low-molecular-weight drugs (LMWDs) for the treatment of COPD and, in addition to the first-line drug bronchodilators, focus particularly on low-molecular-weight anti-inflammatory agents, including modulators of inflammatory mediators, inflammasome inhibitors, protease inhibitors, antioxidants, PDE4 inhibitors, kinase inhibitors, and other agents. We also provide new insights into targeted COPD treatments using LMWDs, particularly small-molecule agents.

Sex Difference in Chronic Obstructive Lung Disease. Does it Matter? A Concise Review

Chronic obstructive lung disease (COPD) primarily affects men; however, its epidemiology has been changing because more women have become smokers. Recently, investigators found that although women and men were exposed to the same amount of smoke fume, women tended to have more severe disease and higher mortality rate. They also complain of more dyspnoea and may experience more severe exacerbations than men. This led to the question of whether sex has an impact on COPD course and whether women have a higher susceptibility to smoke fumes than men. That may be explained by multiple complex factors highlighting the relationship between sex, epidemiology, method of diagnostics and the clinical course of the disease. In this review, sex differences in epidemiology, clinical presentation, exacerbation, co-morbidities and treatment are covered.

Analysis of pulmonary function test results in a health check-up population

BACKGROUND

To explore the incidences of chronic obstructive pulmonary disease (COPD), obstructive ventilatory dysfunction, and obstructive small airway disease and their risk factors in a health check-up population, with an attempt to inform the early diagnosis and treatment of COPD.

METHODS

Subjects who aged 20 years and older and received health check-up in the Health Management Center, Third Xiangya Hospital, Central South University from June 2013 to June 2015 were enrolled in this study. The results of detection and survey for COPD, obstructive ventilatory dysfunction, and obstructive small airway disease were analyzed.

RESULTS

Among 6,811 subjects enrolled in this study, the detection rate of COPD, obstructive ventilator dysfunction, and obstructive small airway disease was 0.8%, 2.6%, and 4.0%, respectively, which showed a positive correlation with male gender, age, and smoking index.

CONCLUSIONS

Health check-up is an important approach for screening COPD, obstructive ventilator dysfunction, and obstructive small airway disease. Smoking cessation and controlling of relevant risk factors are helpful to lower the incidences of these conditions.

Epidemiology of chronic obstructive pulmonary disease: a population-based study in Krasnoyarsk region, Russia

BACKGROUND

Krasnoyarsk region is a territory with the widespread risk factors for chronic obstructive pulmonary disease (COPD) such as tobacco smoke, air pollution, and occupational exposure. An assessment of COPD prevalence based on medical diagnosis statistics underestimates the true COPD prevalence. This study aims to evaluate how medical examinations may increase the accuracy of estimates of COPD prevalence.

METHODS

True COPD prevalence was estimated as a number of patients with the established disease diagnosis supplemented by the additional disease cases detected during medical examinations per 1,000 inhabitants of the region. Official medical statistics data and the data collected from the Global Alliance against Chronic Respiratory Diseases program 2011 among 15,000 inhabitants of the region aged 18 years and older were analyzed.

RESULTS

This study revealed the COPD cases without official medical diagnosis. The true prevalence of COPD is estimated to be two times higher than the prevalence estimates based on medical diagnosis statistics.

CONCLUSION

Undiagnosed and untreated cases of COPD result in severe COPD forms as well as addition of severe comorbidities. Because of this, there is an increase in the index of potential years of life lost. Conducting special medical examinations may increase the number of COPD cases detected at the early stages of the disease. This, in turn, may reduce the overall burden of the disease for the population of the region.

Do females behave differently in COPD exacerbation?

INTRODUCTION

Little is known about whether there is any sex effect on chronic obstructive lung disease (COPD) exacerbations. This study is intended to describe the possible sex-associated differences in exacerbation profile in COPD patients.

METHODS

A total of 384 COPD patients who were hospitalized due to exacerbation were evaluated retrospectively for their demographics and previous and current exacerbation characteristics.

RESULTS

The study was conducted on 109 (28%) female patients and 275 (72%) male patients. The mean age was 68.30±10.46 years. Although females had better forced expiratory volume in 1 second and near-normal forced vital capacity, they had much impaired arterial blood gas levels (partial oxygen pressure [PO2] was 36.28 mmHg vs 57.93 mmHg; partial carbon dioxide pressure [PCO2] was 45.97 mmHg vs 42.49 mmHg; P=0.001), indicating severe exacerbation with respiratory failure. More females had two exacerbations and two hospitalizations, while more men had one exacerbation and one hospitalization. Low adherence to treatment and pulmonary embolism were more frequent in females. Females had longer time from the onset of symptoms till the admission and longer hospitalization duration than males. Comorbidities were less in number and different in women (P<0.05). Women were undertreated and using more oral corticosteroids.

CONCLUSION

Current data showed that female COPD patients might be more prone to have severe exacerbations, a higher number of hospitalizations, and prolonged length of stay for hospitalization. They have a different comorbidity profile and might be undertreated for COPD.