Different Characteristics of Ex-Smokers and Current Smokers with COPD: A Cross-Sectional Study in China

Factors Associated with the Discrepancy between Exercise Capacity and Airflow Limitation in Patients with Chronic Obstructive Pulmonary Disease

BACKGROUND

Exercise capacity is associated with lung function decline in chronic obstructive pulmonary disease (COPD) patients, but a discrepancy between exercise capacity and airflow limitation exists. This study aimed to explore factors contributing to this discrepancy in COPD patients.

METHODS

Data for this prospective study were obtained from the Korean COPD Subgroup Study. The exercise capacity and airflow limitation were assessed using the 6-minute walk distance (6-MWD; m) and forced expiratory volume in 1 second (FEV1). Participants were divided into four groups: FEV1 >50%+6-MWD >350, FEV1 >50%+6- MWD ≤350, FEV1 ≤50%+6-MWD >350, and FEV1 ≤50%+6-MWD ≤350 and their clinical characteristics were compared.

RESULTS

A total of 883 patients (male:female, 822:61; mean age, 68.3±7.97 years) were enrolled. Among 591 patients with FEV1 >50%, 242 were in the 6-MWD ≤350 group, and among 292 patients with FEV1 ≤50%, 185 were in the 6-MWD >350 group. The multiple regression analyses revealed that male sex (odds ratio [OR], 8.779; 95% confidence interval [CI], 1.539 to 50.087; p=0.014), current smoking status (OR, 0.355; 95% CI, 0.178 to 0.709; p=0.003), and hemoglobin levels (OR, 1.332; 95% CI, 1.077 to 1.648; p=0.008) were significantly associated with discrepancies in exercise capacity and airflow limitation in patients with FEV1 >50%. Meanwhile, in patients with FEV1 ≤50%, diffusion capacity of carbon monoxide (OR, 0.945; 95% CI, 0.912 to 0.979; p=0.002) was significantly associated with discrepancies between exercise capacity and airflow limitation.

CONCLUSION

The exercise capacity of COPD patients may be influenced by factors other than airflow limitation, so these aspects should be considered when assessing and treating patients.

Development and validation of a nomogram model for mortality prediction in stable chronic obstructive pulmonary disease patients: A prospective observational study in the RealDTC cohort

Background

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide. There is no nomogram model available for mortality prediction of stable COPD. We intended to develop and validate a nomogram model to predict mortality risk in stable COPD patients for personalised prognostic assessment.

Methods

A prospective observational study was made of COPD outpatients registered in the RealDTC study between December 2016 and December 2019. Patients were randomly assigned to the training cohort and validation cohort in a ratio of 7:3. We used Lasso regression to screen predicted variables. Further, we evaluated the prognostic performance using the area under the time-dependent receiver operating characteristic curve (AUC) and calibration curve. We used the AUC, concordance index, and decision curve analysis to evaluate the net benefits and utility of the nomogram compared with three earlier prediction models.

Results

Of 2499 patients, the median follow-up was 38 months. The characteristics of the patients between the training cohort (n = 1743) and the validation cohort (n = 756) were similar. ABEODS nomogram model, combining age, body mass index, educational level, airflow obstruction, dyspnoea, and severe exacerbation in the first year, was constructed to predict mortality in stable COPD patients. In the integrative analysis of training and validation cohorts of the nomogram model, the three-year mortality prediction achieved AUC = 0.84; 95% confidence interval (CI) = 0.81, 0.88 and AUC = 0.80; 95% CI = 0.74, 0.86, respectively. The ABEODS nomogram model preserved excellent calibration in both the training cohort and validation cohort. The time-dependent AUC, concordance index, and net benefit of the nomogram model were higher than those of BODEx, updated ADO, and DOSE, respectively.

Conclusions

We developed and validated a prognostic nomogram model that accurately predicts mortality across the COPD severity spectrum. The proposed ABEODS nomogram model performed better than earlier models, including BODEx, updated ADO, and DOSE in Chinese patients with COPD.

Registration

ChiCTR-POC-17010431.

The clinical characteristics and outcomes of different inhaled therapies in chronic obstructive pulmonary disease patients with frequent cough

BACKGROUND

Cough is a common symptom in patients with chronic obstructive pulmonary disease (COPD). Patients with cough may exhibit various clinical characteristics and experience varying outcomes based on inhaled therapies they receive.

OBJECTIVES

This study aimed to explore the clinical characteristics and outcomes of various inhaled therapies in COPD patients with frequent cough.

METHODS

This was a multicenter, prospective cohort study. Of these patients, the median cough score in COPD assessment test (CAT) was two. Patients were classified into frequent cough group if they scored two or over in the first item of CAT and infrequent cough group otherwise. Patients with frequent cough were then divided into long-acting antimuscarinic (LAMA), long-acting beta2-agonist (LABA)/LAMA, inhaled corticosteroids (ICS)/LABA and ICS/LABA/LAMA groups. Minimum clinically important difference (MCID) (CAT scores decreased ≥2 from baseline) and the improvement of cough (cough score decreased ≥1 from baseline) were collected in the six-month follow-up. Frequent exacerbations (experiencing at least two exacerbations) were collected in the one-year follow-up.

RESULTS

Of 906 patients, 581 (64.1%) patients reported frequent cough at the initial visit. Frequent cough was associated with the current smokers and CAT scores (p < 0.05). The MCID showed no significant difference between frequent cough and infrequent cough groups in the follow-up. More patients with frequent cough experienced future frequent exacerbations compared to those with infrequent cough. After receiving inhaled therapies, 62% of patients with frequent cough got the cough improved. More patients with frequent cough treated with LABA/LAMA or ICS/LABA/LAMA attained MCID and fewer experienced exacerbations than those treated with LAMA or ICS/LABA (p < 0.05). The change in cough score showed no difference among various inhaled therapies in patients with frequent cough.

CONCLUSION

COPD patients with frequent cough were related to current smokers and higher CAT scores. These patients had a higher incidence of frequent exacerbations than those with infrequent cough. Patients with frequent cough who were treated with LABA/LAMA or ICS/LABA/LAMA were more likely to attain MCID and at a lower risk of exacerbation than those treated with LAMA or ICS/LABA.

Prediction of Hospitalization and Mortality in Patients with Chronic Obstructive Pulmonary Disease with the New Global Initiative for Chronic Obstructive Lung Disease 2023 Group Classification: A Prospective Cohort and a Retrospective Analysis

Background

The revised Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2023 group ABE classification has undergone major modifications, which can simplify clinical assessment and optimize treatment recommendations for Chronic Obstructive Pulmonary Disease (COPD). However, the predictive value of the new grouping classification for prognosis is worth further exploration. We aimed to compare the prediction of hospitalization and mortality between this new GOLD group 2023 ABE classification and the earlier 2017 ABCD classification in a Chinese COPD cohort.

Methods

Data from 2,499 outpatients with COPD, who first registered in the RealDTC study of Second Xiangya Hospital from December 2016 to December 2019, were collected prospectively and assessed retrospectively. Patients were followed up on all-cause mortality until October 2022 or death.

Results

Of the 2,499 patients with COPD, the risk of hospitalization during the first-year follow-up was higher in group E than in groups A and B. The mortality was higher in group E than in groups A and B, and group B was higher than group A. No differences were seen in the area under the curve (AUC) of 2017 vs 2023 GOLD grouping to predict hospitalization. The time-dependent AUC and concordance index for predicting mortality is slightly higher in the GOLD 2017 ABCD than in the 2023 ABE groups. The new GOLD 12-subgroup (1A-4E) classification combining the GOLD 1-4 staging and grouping performed similarly discriminate predictive power for mortality to the GOLD 2017 16-subgroup (A1-4D) classification.

Conclusion

The risk of hospitalization during the first-year follow-up was higher in group E than in groups A and B. The all-cause mortality increased gradually from GOLD group A to E. The GOLD 2023 classification based on ABE groups did not predict mortality better than the earlier 2017 ABCD classifications.

Social Participation and Persistent Smoking Among Older Chinese With Smoking-Related Morbidity

OBJECTIVES

Chronic diseases are common in midlife and old age and smoking can pose more health and longevity challenges for older people with chronic illnesses. In China where smoking is highly prevalent, older adults are likely to continue smoking even after developing severe chronic diseases. We examined the national prevalence of persistent smoking among older adults. We also investigated the sociodemographic characteristics of persistent smoking among ever-smokers with chronic diseases and its association with social participation (of various types).

METHODS

We used data from a nationally representative sample of older adults aged 45-80 in the China Health and Retirement Longitudinal Study (2011-2018). Multinomial logistic and multilevel logistic models were fitted.

RESULTS

The national prevalence of persistent smoking was around 24% of older men and 3% of older women. Among those with a history of smoking and chronic illness, younger, nonmarried/partnered, nonretired, or less educated individuals are more likely to continue smoking. Social participation is significantly associated with persistent smoking among those with chronic diseases, but the association differs across different forms of activities. Although the most popular but sedentary activities in China (playing Mahjong, chess, or cards) are associated with an elevated risk of persistent smoking, physical social activities (community-organized dancing, fitness, and qigong) are associated with a reduced risk of persistent smoking.

DISCUSSION

Given the enormous burden of persistent smoking on individuals and society, public smoking cessation inventions should address sociocultural factors of persistent smoking and target older adults who participate in specific social activities.

The clinical characteristics of patients with asthma exposed to different environmental risk factors: A cross-sectional study

BACKGROUND

Smoking, biomass, and occupational exposure are the main environmental risk factors for asthma. The purpose of this study was to analyze the clinical characteristics of exposure to these risk factors in patients with asthma.

METHODS

This cross-sectional study enrolled patients with asthma from an outpatient department according to the Global Initiative for Asthma. Demographics, forced expiratory volume in 1 s (FEV1), FEV1%pred, FEV1/forced vital capacity (FVC), laboratory tests, asthma control test (ACT), asthma control questionnaire (ACQ) scores, and the inhaled corticosteroid (ICS) dose were recorded. A generalized linear mixed model was used to adjust for potential confounders.

RESULTS

A total of 492 patients with asthma were included in this study. Of these patients, 13.0% were current smokers, 9.6% were former smokers, and 77.4% were never smokers. Compared with never smokers, the current and former smokers had a longer duration of asthma; lower ACT scores, FEV1, FEV1%pred, and FEV1/FVC; and higher ACQ scores, IgE, FeNO, blood eosinophils, and ICS dose (p < .05). In addition, the patients exposed to biomass alone were older; had higher exacerbation in the past year; a longer duration of asthma; and lower FEV1, FEV1%pred, FEV1/FVC, IgE, and FeNO compared with smoking or occupational exposure alone. Compared with smoking exposure alone, patients with occupational exposure alone had a longer duration of asthma and lower FEV1, FEV1%pred, FVC, IgE, FeNO, and ICS dose (p < .05).

CONCLUSIONS

There are significant differences in the clinical characteristics of patients with asthma depending on the smoking status. In addition, significant differences also observed among smoking, biomass, and occupational exposure.

Interaction of smoking and social status on the risk of respiratory outcomes in a Swedish adult population: A Nordic Epilung study

BACKGROUND

Evidence abounds on the independent roles of social class and smoking in relation to obstructive airway diseases, but data are sparse on the impact of their interaction. We evaluated whether and to what extent social class and smoking interact in relation to risk of respiratory diseases in adults.

METHODS

Data from the population-based studies, West Sweden Asthma Study (WSAS, n = 23,753) and Obstructive Lung Disease in Northern Sweden studies (OLIN, n = 6519), were used, constituting randomly selected adults aged 20-75 years. Bayesian network analysis was used to estimate the probability for the interaction between smoking and socioeconomic status in relation to respiratory outcomes.

RESULTS

Occupational and educational SES modified the association between smoking and the probability of allergic and non-allergic asthma. Former smokers who were at intermediate non manual employees and manual workers in service had higher probability of allergic asthma compared to professionals and executives. Furthermore, former smokers with primary education had higher probability of non-allergic asthma than those with secondary and tertiary education. Similarly, former smokers among professionals and executives had higher probability of non-allergic asthma than manual and home workers and primary educated. Likewise, allergic asthma due to former smoking was higher among highly educated compared to low educated.

CONCLUSIONS

Beyond their independent roles, socioeconomic status and smoking interact in defining the risk of respiratory diseases. Clearer understanding of this interaction can help to identify population subgroups at most need of public health interventions.

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.

Real-World Effectiveness of Inhalation Therapy Among Patients With Symptomatic COPD in China: A Multicenter Prospective Study

Purpose: This real-world study evaluated the effectiveness of different inhalation therapies in patients with symptomatic chronic obstructive pulmonary disease (COPD) in China and also explored the relevant factors that influence the effectiveness of inhalation therapy.

Patients and Methods: We conducted a multicenter prospective longitudinal study that was carried out in 12 hospitals in China from December 2016 to June 2021. A face-to-face interview was conducted to collect data. Baseline data were collected at the first visit. Minimum clinically important difference (MCID) was defined as attaining a COPD assessment test (CAT) decrease ≥2. We mainly assessed the MCID and the incidence of exacerbations at the 6 months follow-up.

Results: In 695 patients, the mean age was 62.5 ± 8.2 years, with a mean CAT score of 15.1 ± 6.0. Overall, 341 (49.1%) patients attained the MCID of CAT and the incidence of exacerbation during follow-up was 22.3%. Females were significantly more likely to attain MCID than male in COPD patients (adjusted odd ratio (aOR) = 1.93, adjusted 95% confidence interval (a95%CI) = 1.09–3.42, p = 0.024). Patients treated with LABA/LAMA or ICS/LABA/LAMA (ICS, inhaled corticosteroid; LABA, long-acting β2-agonist; LAMA, long-acting muscarinic antagonist) were more likely to attain MCID than patients treated with LAMA (aOR = 3.97, a95%CI = 2.48–6.35, p < 0.001; aOR = 3.17, a95%CI = 2.09–4.80, p < 0.001, respectively). Patients treated with LABA/LAMA had a higher incidence of severe exacerbation than patients treated with ICS/LABA/LAMA (aOR = 1.95, a95%CI = 1.04–3.66, p = 0.038).

Conclusion: The incidence of MCID in symptomatic COPD patients treated with inhalation therapy was nearly 50%. Patients treated with LABA/LAMA or ICS/LABA/LAMA were more likely to attain MCID than patients treated with LAMA. Patients treated with LABA/LAMA had a higher incidence of severe exacerbations than with ICS/LABA/LAMA.

TREM-1 aggravates chronic obstructive pulmonary disease development via activation NLRP3 inflammasome-mediated pyroptosis

OBJECTIVES

Chronic obstructive pulmonary disease (COPD) is a major cause of death globally. Inflammation plays a crucial role in COPD development. Pyroptosis, an inflammatory form of cell death, may involve in the pathogenesis of COPD. This study aims to explore the role and action mechanism of triggering receptor expressed on myeloid cells 1 (TREM-1) in COPD.

METHODS

Here, cigarette smoke stimulation was used to establish COPD model in mice. Cigarette smoke extract combined with lipopolysaccharide was used to stimulate RAW264.7 cells for COPD model in vitro. QRT-PCR and Western blot were performed to detect the expression of mRNA and proteins, respectively, in the lung tissues and cells. Concentration of cytokines was measured using ELISA. H&E staining was used to analyze the pathological changes in lung tissues. The number of infiltrated macrophage was examined using immunofluorescence. LP17 was used to silence the expression of TREM-1.

RESULTS

The results showed that TREM-1 was highly expressed in COPD. In vivo, inhibition of TREM-1 effectively improved the injury in lung tissues of COPD mouse, and reduced the infiltration of macrophages. Moreover, inhibition of TREM-1 in vivo and in vitro notably suppressed the activation of NLRP3 inflammasome and pyroptosis. Rescue experiment demonstrated that TREM-1 activated pyroptosis via regulating NLRP3 inflammasome.

CONCLUSION

Overall, our results proved that TREM-1 promoted the lung injury and inflammation in COPD mouse through activation of NLRP3 inflammasome-mediated pyroptosis. Our data indicated a novel mechanism of TREM-1 in COPD development, and maybe provide a novel therapeutic target for COPD treatment.

The Characteristics of Airflow Limitation and Future Exacerbations in Different GOLD Groups of COPD Patients

Background

The Global Initiative for Chronic Obstructive Lung Disease (GOLD) 2017 separated pulmonary function from combined assessment. We aimed to analyze the characteristics of airflow limitation and future exacerbations in different GOLD groups of chronic obstructive pulmonary disease (COPD) patients.

Methods

For this prospective observational study, stable COPD outpatients were enrolled and divided into Groups A, B, C and D based on GOLD 2017, and followed-up for 18 months. Data on demographics, pulmonary function, COPD assessment test (CAT), Clinical COPD Questionnaire (CCQ), modified Medical Research Council (mMRC), exacerbations, mortality and treatments were collected. A post-bronchodilator ratio of forced expiratory volume in one second to forced vital capacity <0.70 confirms the presence of airflow limitation.

Results

A total of 993 subjects were classified into Groups A (n = 170, 17.1%), B (n = 360, 36.3%), C (n = 122, 12.3%), and D (n = 341, 34.3%). There were significant differences in mMRC, CAT, CCQ, exacerbations and hospitalizations rates among the different groups (P < 0.001). Groups B and D had more severe airflow limitation than Groups A and C (P < 0.05). In the same groups with different severity of airflow limitation, the differences were mainly observed in body mass index, CAT, CCQ and treatment with long-acting muscarinic antagonist (LAMA) and LAMA + long-acting β2-agonist + inhaled corticosteroid (P < 0.05). After 18 months of follow-up, the exacerbations and hospitalizations rates were significantly different among different groups (P < 0.05). However, in the same groups with different airflow limitation severity, the mortality rates and number of exacerbations, hospitalizations and frequent exacerbators showed no differences.

Conclusion

In the GOLD groups, different severity of airflow limitation had no impact on future exacerbations and mortality rate. It implies that pulmonary function is not a good indicator for predicting exacerbation.

Liuzijue is a promising exercise option for rehabilitating discharged COVID-19 patients

BACKGROUND

Among discharged COVID-19 patients, the health-related quality of life is poor, and patients suffer from significant physical and psychological impairment. This study was designed to investigate the effects of Liuzijue exercise on the rehabilitation of COVID-19 patients.

METHODS

Thirty three eligible patients with COVID-19 were enrolled in the study after discharge. All the participants practiced Liuzijue exercise once per day for 20 minutes over 4 weeks. Data were collected at baseline and the end of the intervention. Primary outcomes involved functional capacity and secondary outcomes involved quality of life.

RESULTS

The maximal inspiratory pressure (MIP), peak inspiratory flow (PIF), and diaphragm movement in deep breathing (DM-DB) of patients increased significantly after 4 weeks of intervention. The dyspnea was also alleviated and exercise capacity was significantly improved. In terms of quality of life, physical functioning and role-physical scores were significantly increased. Moreover, Liuzijue could significantly alleviate the depression and anxiety status of the patients.

CONCLUSION

Liuzijue exercise is a viable alternative home exercise program that produced better functional capacity and quality of life in discharged patients with COVID-19. These findings also showed the necessity of rehabilitation intervention for cured COVID-19 patients.