Asthma and chronic obstructive pulmonary disease overlap (ACO) is a hot topic in recent years. Although the precise definition of ACO is still controversial, scholars have found that the patients with overlapping features of asthma and COPD have a worse prognosis and increased medical cost than those with asthma or COPD alone. Thus, there is a big challenge to have a better understanding and to manage these patients in clinical practice. To strengthen awareness of this type of patients, the Global initiative for Chronic Obstructive Lung Disease (GOLD) and Global initiative for asthma (GINA) in 2014 named them as " Asthma Chronic Obstructive Lung Overlap Syndrome" (ACOS), which was further revised to the Asthma Chronic Obstructive Lung Overlap (ACO) in the follow-up GINA guidelines (2017). In the updated version, it emphasized that ACO was not a separate disease. However, although the research on ACO has increased significantly in recent years, there are still many controversies, which includes the definition, diagnostic criteria and treatment therapies. In this review, we provide the recent advances in the diagnosis and an overview of available treatment for of ACO.

Objective:To explore the predictive value of exhaled nitric oxide (FeNO) for the risk of acute exacerbation in stable chronic obstructive pulmonary disease (COPD) patients over the next year and evaluate whether it can guide the use of inhaled corticosteroids (ICS).Methods:This study was a multicenter, retrospective and observational cohort study. The subjects of this study were stable COPD patients who were hospitalized in 12 hospitals in Hunan Province and Guangxi from January 2017 to December 2021. The patient′s basic Demography information, previous acute exacerbation history, pulmonary function, FeNO, chronic obstructive pulmonary disease assessment test questionnaire (CAT) score, modified British Medical Research Council dyspnea questionnaire (mMRC) score, chronic obstructive pulmonary disease control questionnaire (CCQ) score, and detailed treatment plan were collected. Based on FeNO 25 ppb, patients were divided into a high FeNO group and a normal FeNO group. All patients were followed up for 1 year and information on acute exacerbation was recorded.Results:A total of 825 patients were included, aged (63.5±9.1)years, with a median of 25 ppb of FeNO. A number of 825 patients were followed up for 1 year, of which 262(31.8%) experienced acute exacerbation. Multivariate logistic regression found that FeNO, CAT score, smoking cessation, and past history of acute exacerbation were independent factors predicting acute exacerbation in COPD patients in the next year (all P<0.05). High FeNO was a protective factor for acute exacerbation in COPD patients in the next year, with an OR value of 0.10 ( P<0.001). Further analysis found that the proportion of patients in the high FeNO group using ICS was significantly higher than that in the normal FeNO group [58.8%(247/420) vs 48.6%(197/405), P=0.003]. In the high FeNO group, using ICS can reduce the incidence of acute exacerbation of COPD in the next year [8.9%(22/247) vs 15.6%(27/173), P<0.05], while in the normal FeNO group, there was no statistically significant difference in the frequency of acute exacerbation between patients using ICS and those not using ICS ( P>0.05). Conclusions:FeNO is an independent factor predicting the acute exacerbation of COPD in the next year, and patients with high FeNO levels may consider using ICS in combination.

Objective:To understand the use of inhaled corticosteroids (ICS) in patients with chronic obstructive pulmonary disease (COPD) in the real world and analyze its compliance with the guidelines.Methods:This study is a multicenter, cross-sectional study. 1 051 COPD patients who were treated in the Second Xiangya Hospital of Central South University, the First Affiliated Hospital of Shaoyang College and Zhuzhou Central Hospital from January 2020 to March 2022 were collected. The general information, drug use, types of exposure risk factors, acute exacerbation (AE) in the past year, the scores of the modified British Medical Research Council Dyspnea Questionnaire (mMRC), COPD Assessment Test (CAT), pulmonary function, blood routine of patients were collected. The status of ICS use in COPD patients, the clinical characteristics and guideline compliance of non-ICS users and ICS users were analyzed.Results:Among 1 051 patients with COPD, ICS was used in 490 cases (46.6%) and was not used in 561 cases (53.4%). ICS use was associated with relapse, frequent AE, severe AE, Global Initiative for Chronic Obstructive Pulmonary Disease (GOLD) grade 2 or above, GOLD D group, mMRC score, bronchial asthma, and blood eosinophils (EOS) (all P<0.05). Among 1 051 patients, 583(55.5%) were newly treated, 222(38.1%) were newly treated with ICS, and 361(61.9%) were not treated with ICS. ICS use in newly treated patients was associated with frequent AE, severe AE in the past year, GOLD grade 2 to 3, GOLD B and D group, mMRC score, bronchial asthma, and blood EOS (all P<0.05). Conclusions:Nearly half of patients with COPD are treated with ICS, and patients with ICS use had a higher risk of AE, more severe symptoms, higher blood EOS, and higher rates of asthma. However, there still exists the phenomenon of overuse of ICS.

Objective:To observe the clinical characteristics and guideline compliance of chronic obstructive pulmonary disease (COPD) patients with initial triple therapy in real-life world.Methods:This study is a cross-sectional study. The subjects of the study were COPD patients admitted to 13 hospitals in Hunan Province and Guangxi Zhuang Autonomous Region from December 2016 to December 2021. The initial treatment was triple inhaled drugs. The data collected included gender, age, diagnosis, body mass index (BMI), history of acute exacerbation (AE) in the past year, pulmonary function, COPD Assessment Test (CAT) score, modified British Medical Research Council Dyspnea Questionnaire (mMRC), inhaled drugs and other indicators. The characteristics and differences of COPD patients before and after 2020 were analyzed.Results:7 184 patients with COPD were enrolled in this study, including 2 409 COPD patients treated with initial triple therapy, accounting for 33.5%(2 409/7 184). Taking January 1st, 2020 as the cut-off point, 1 825 COPD patients (75.8%) received initial treatment with triple inhaled drugs before 2020 and 584 patients (24.2%) after 2020 were included in this study. Compared with COPD patients before 2020, the COPD patients after 2020 had higher FEV 1% [(40.9±15.5 )% vs (39.3±15.5)%, P=0.040], lower CAT [(15.8±6.5)point vs (17.5±6.2)point, P<0.001], less AE in the past year [1(0, 2)times vs 1(0, 2)times, P=0.001] and higher rate of non-AE [255(43.7%) vs 581(37.1%), P=0.006]. In addition, before 2020, patients with COPD were mainly treated with open triple drugs (1 825/1 825, 100%); after 2020, 306 patients (52.4%) received open triple inhaled drugs, and 278 patients (47.6%) received closed triple inhaled drugs. Conclusions:In real-life world, most of patients with COPD treated with triple therapy have severe lung function, obvious symptoms and high risk of acute exacerbation. The real-world prescribing of triple therapy in patients with COPD does not always reflect recommendations in guidelines and strategies, and overtreatment is common. After 2020, prescribing triple therapy for COPD patients is more positive and worse consistency with guideline.