Impact of long-acting muscarinic antagonists on small airways in asthma and COPD: A systematic review

Efficacy and safety of long-acting muscarinic antagonists in COPD: A meta-analysis and meta-regression with a focus on aging

The increasing global elderly population, projected to reach 20 % of individuals aged 65 and over by 2030, faces significant pulmonary challenges, including chronic obstructive pulmonary disease (COPD). Aging is associated with a natural decline in lung function and structural changes that exacerbate respiratory issues. COPD, characterized by chronic respiratory symptoms and airflow obstruction, presents a unique challenge in older patients due to the accelerated decline in lung function. Acetylcholine plays a pivotal role in airway dynamics through muscarinic acetylcholine receptors, particularly M3 subtype, which mediates bronchoconstriction. The efficacy of long-acting muscarinic antagonists (LAMA) may differ in older adults, with evidence suggesting that these patients can respond favorably to LAMA treatment. This study utilized meta-analysis and meta-regression to explore the efficacy and safety of LAMA in treating COPD, while considering aging as a potential modifier. A meta-analysis of Phase III randomized controlled trials highlighted significant improvements in trough forced expiratory volume in the 1st second when LAMA were compared to placebo (PCB). Furthermore, the meta-regression revealed a trend suggesting older adults may experience enhanced benefits from LAMA therapy, particularly with once-daily regimens. Safety outcomes, including serious adverse events (SAE), cardiovascular SAE, and mortality, were not modulated by age when comparing LABA to PCB. Overall, these findings support the use of LAMA in elderly COPD patients and underscore the need for tailored treatment strategies to improve clinical outcomes in this vulnerable population.

The prevalence of small airways disease and association with handgrip strength in young Hispanic farmworkers

BACKGROUND

Small airways disease (SAD) is a key risk in developing obstructive lung diseases (OLD). Handgrip strength (HGS) is found to be associated with pulmonary function in populations with lung conditions. Hispanics remain the main workforce in farming industry, but their prevalence of lung conditions remain understudied. Likewise, HGS also remains understudied in Hispanic and farmworker populations. Our study investigated the prevalence of SAD and OLD as well as their associations with HGS among Hispanic farmworkers.

METHODS

A cross-sectional study analyzed 113 Hispanic farmworkers (54% female) who were screened using pulmonary function tests during annual health fairs in rural Southeastern US from 2013 to 2017. Smoking status was self-reported. SAD was defined as forced expiratory flow at 25-75% predicted of vital capacity (FEF25-75%predicted) ≤ 60% per literature and OLD defined as forced expiratory volume in 1 s/ forced vital capacity (FEV1/FVC) ratio < 70% per Global Initiative for Chronic Obstructive Lung Disease criteria. Seated isometric absolute (the sum of both hands) and relative (absolute handgrip strength divided by body mass index) handgrip strengths were collected.

RESULTS

26.5% of subjects had SAD and 15.9% had OLD. 50% of subjects with SAD had OLD while 83% of subjects with OLD had SAD. 13% of overall population smoked. Lower absolute and relative HGS groups had higher prevalence of SAD and OLD. Multivariate linear regression showed that lower absolute and relative HGS were associated with worsened small airway function. Age and FEF25-75%predicted were associated with FEV1/FVC. Smoking, body mass index, blood pressures, hemoglobin A1C and lipids were not predictors in either model.

CONCLUSIONS

This is one of the first studies reporting prevalence of pulmonary function in Hispanic farmworkers. Although this population was relatively young and healthy, there was high prevalence of SAD and OLD, which was higher than the overall prevalence in Hispanic population. There were more females subjects with SAD. Most of the subjects with OLD had SAD but not vice versa. Lower HGS levels were associated with worsened pulmonary function, and HGS was a significant predictor of FEF25-75%predicted, a potential marker for small airway physiology.

The impact of wearing facemask on COPD patients: A protocol of a systematic review and meta-analysis

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) is a common, irreversible but preventable disease characterized by persistent respiratory symptoms. The mortality rate of COPD is predicted to reach 5.4 million by the year 2060. Despite its heavy burden on healthcare expenditure worldwide, only 15% of cases are medically identified. The potential benefits of facemask-wearing for COPD patients remain a topic of debate.

METHODS

We will conduct a systematic review of all randomized trials and non-randomized controlled trials to evaluate the impact of facemasks on COPD patients. Our review will be based on literature obtained through a comprehensive search strategy across multiple electronic databases, including the Cochrane Library, Embase, PubMed, Web of Science, the Chinese Biomedical Database (SinoMed), and China National Knowledge Infrastructure (CNKI), with no restrictions on language or date of publication. Two independent researchers will extract and assess all relevant data using pre-designed data extraction forms. The included studies will be assessed using the Cochrane RoB2 tool and the suggested risk of bias criteria proposed by the Effective Practice and Organization of Care reviews group of the Cochrane collaboration. The quality of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. We will use Review Manager 5.4 software for statistical analysis.

DISCUSSION

In the context of COVID-19, it is important for COPD patients to wear facemasks. This study aims to conduct a comprehensive and systematic assessment of the impact of facemasks on the physiology and activity of COPD patients.

TRIAL REGISTRATION

PROSPERO registration number CRD42022326265.

Residual Dyspnea May Predict Small Airways Dysfunction and Poor Responsiveness to Single-Inhaler Triple Therapy in Asthmatic Patients

PURPOSE

Recently, single-inhaler triple therapy (SITT) has demonstrated efficacy in patients with uncontrolled asthma who were symptomatic despite treatment with inhaled corticosteroids/long-acting β2 agonists. However, the characteristics of patients who benefit from SITT remain unclear in the real-world. The aim of this study was to examine the predictors of responsiveness to SITT in patients with asthma.

PATIENTS AND METHODS

A total of 45 patients with asthma who had regularly visited our respiratory clinic and were started on SITT from March 2019 to March 2021 were retrospectively analyzed. Patients' demographic characteristics, residual respiratory symptoms, type 2 biomarkers, and lung function before SITT were assessed from the patients' medical records. Predictors of responsiveness to four-week SITT were evaluated in these patients. The definition of responders was based on the physician-assessed global evaluation of treatment effectiveness.

RESULTS

Thirty-four (75%) of 45 patients were identified as responders to SITT. Non-responders showed significantly lower forced vital capacity (FVC) (%predicted) values, and complained of dyspnea more frequently than responders before SITT (p = 0.01 and p = 0.02, respectively). There were no significant differences in demographic characteristics and type 2 biomarkers between responders and non-responders. Clinical predictors of poor response to SITT were residual dyspnea (OR = 0.14, p = 0.02), low FVC (%predicted) values (OR = 1.05, p = 0.01), and FVC (%predicted) <80% (OR = 0.11, p = 0.02). Multivariate analysis showed that poor response to SITT was associated with residual dyspnea before SITT (OR = 0.14, p = 0.02). On the other hand, patients with residual dyspnea had significantly lower FEF_25-75 (%predicted) values than patients without residual dyspnea before SITT (p = 0.04).

CONCLUSION

Residual dyspnea, reflecting small airways dysfunction, may predict poor responsiveness to short-term SITT in patients with asthma.

The impact of long-acting muscarinic antagonists on mucus hypersecretion and cough in chronic obstructive pulmonary disease: a systematic review

Patients suffering from chronic obstructive pulmonary disease (COPD) clinically manifest airway mucus hypersecretion as sputum expectoration and cough. Evidence accumulated in the past decade has shown that the cholinergic system not only regulates airway smooth muscle contraction but also the activity of inflammatory and airway epithelial cells, including goblet cells, and submucosal gland activity. Long-acting muscarinic antagonists (LAMAs) with the most favourable M₃/M₂ muscarinic acetylcholine (ACh) receptors residency properties are not only excellent bronchodilators but potentially also mucus-modifying agents, able to positively impact on mucus hypersecretion and cough. The aim of this systematic review was to investigate the impact of LAMAs on mucus hypersecretion and cough in COPD patients. The evidence confirmed that LAMAs, mainly tiotropium and aclidinium, improved sputum production and cough in moderate to severe COPD. Thus, LAMAs not only antagonise the ACh-induced bronchoconstriction of the airways but also appear to limit the production of mucus secreted in response to ACh by airway goblet cells and/or submucosal glands. Further clinical studies are necessary to evaluate the impact of LAMAs exclusively on sputum symptoms and cough as primary end-points and to investigate whether LAMAs have a modulatory action on the rheological properties of mucus.