Asthma-chronic obstructive pulmonary disease overlap in China: prevalence, associated factors and comorbidities in middle-aged and older adults

The association between abdominal obesity and pulmonary function trajectories among patients with COPD

The association between abdominal obesity and pulmonary function trajectories among patients with COPD remain to be unclear. This study aimed to explore the association between abdominal obesity and pulmonary function trajectories among patients with COPD. Data were collected from the China Health and Retirement Longitudinal Study, which was a nationally representative investigation. The pulmonary function indicator was peak expiratory flow (PEF). Abdominal obesity was assessed using waist circumference, which was categorized into two groups: < 90/85 cm and ≥ 90/85 cm, in men/women. Latent class growth analysis was used to identify distinct pulmonary function trajectories. The logistic regression was used to assess the association between abdominal obesity and pulmonary function trajectories. Finally, a total of 775 patients with COPD aged 45 years and older were included, and 301 participants (38.84%) were abdominal obesity. The mean PEF value showed a decreasing trend, with respective average values of 205.84 L/min (SD = 104.16), 199.99 L/min (SD = 99.52), and 196.06 L/min (SD = 86.74) in 2011, 2013 and 2015. Two PEF trajectories were identified: "above average-high descending" trajectory (n = 187, 24.13%) and "low-maintenance" trajectory (n = 588, 75.74%). Unadjusted and adjusted analysis showed that baseline higher waist circumference was associated with "low-maintenance" trajectory. A negative association between abdominal obesity and pulmonary function trajectories was observed among patients with COPD. This suggests that increased abdominal fat may accelerate the decline of pulmonary function over time. These findings provide evidence for designing targeted programs to improve pulmonary function, particularly for patients with COPD of abdominal obesity.

Exploring the association between socioeconomic inequalities in chronic respiratory disease and all-cause mortality in China: findings from the China Health and Retirement Longitudinal Study

Objective

Research on the inequality of chronic respiratory disease (CRD) is limited, and the association between CRD and all-cause mortality is not well-established. Investigating the distribution of CRD and its associated mortality risks is essential for improving CRD conditions and developing targeted intervention measures. This study aimed to explore the relationship between inequalities in CRD and all-cause mortality in China.

Methods

This study utilized nationally representative baseline data from the China Health and Retirement Longitudinal Study (CHARLS, 2011-2020, wave 1-wave 5), including a total of 14,743 subjects. The concentration index was employed to measure socioeconomic-related inequality in CRD, and the concentration index decomposition method was used to describe its influencing factors. Cox proportional hazards regression model was employed to examine the association between CRD and all-cause mortality.

Results

The prevalence of CRD was 11.79% (95% CI: 10.98, 12.66) in China. The concentration index for CRD was -0.050 (95% CI: -0.075, -0.026), indicating a certain degree of inequality in its prevalence. Chronic lung disease (concentration index = -0.046, 95% CI: -0.073, -0.019), asthma (concentration index = -0.102, 95% CI: -0.148, -0.056), and asthma-chronic obstructive pulmonary disease overlap syndrome (concentration index = -0.114, 95% CI: -0.173, -0.055) also exhibited a pro-poor distribution. The decomposition analysis of the concentration index for CRD revealed that age, education level, and economic status played substantial roles in contributing to the observed inequality. Additionally, Cox regression analysis showed that participants with CRD had an increased risk of all-cause mortality (HR = 1.49, 95% CI: 1.34, 1.65).

Conclusion

Inequalities exists in CRDs in China, with the prevalence of these diseases primarily concentrated among economically disadvantaged groups. Additionally, CRD increases the risk of all-cause mortality. Addressing the root causes of economic inequalities and enhancing the educational attainment of individuals with low socioeconomic status can help improve the situation.

Association between chronic respiratory diseases and frailty in Chinese elderly: a population-based longitudinal study

BACKGROUND

Chronic respiratory diseases (CRDs) have been shown to be associated with frailty, but these findings have not yet reached a consensus. The aim of this study was to investigate the association between CRDs and frailty in the elderly using a nationally representative data from China.

METHODS

Data from the China Health and Retirement Longitudinal Study (CHARLS) were analysed, including 3309 frailty-free participants followed for three waves from 2011. Frailty was assessed using the physical frailty phenotype scale, and CRDs were conformed by self-reported physician diagnoses. Cox proportional hazard models were used to examine the association between baseline CRDs and subsequent frailty.

RESULTS

Among participants (mean age 67.07 years, 51.53% male), 497 (15.02%) had CRDs. During a mean follow-up of 46 months, 273 (8.25%) participants developed frailty. The incidence rate of frailty was significantly higher in the CRDs group (37.17% per 1000 person-years vs 18.41% per 1000 person-years, p<0.01). Adjusted for covariables, participants with CRDs had a 44% higher risk of developing frailty (HR = 1.44, 95% CI: 1.08 to 1.91). Specifically, asthma only (HR=1.89, 95% CI: 1.07 to 3.33) and asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) (HR=1.79, 95% CI: 1.19 to 2.69) were associated with a higher risk of frailty among the elderly, while COPD only was not (HR=1.11, 95% CI: 0.73 to 1.65).

CONCLUSION

This study shows a significant association between CRDs, particularly asthma only and ACO, and frailty in the elderly. We need to pay attention to the frailty status of CRDs patients and consider routine screening among them in both clinical practice and community settings. Active treatment and control of CRDs are necessary to avoid frailty caused by primary lung disease progression or exacerbation.

Association between Sleep Duration and Hand Grip Strength among COPD Patients

This study aimed to evaluate the association between night-time sleep duration and hand grip strength (HGS) among patients with chronic obstructive pulmonary disease (COPD). Participants aged ≥45 years were included in a nationally representative investigation clinical study in 2015. HGS was measured using dynamometers. The data on night-time sleep duration, sociodemographic information, and health-related variables were systematically collected. For analysis, sleep duration was categorized as <5 h, 5-7 h, 7 h, 7-9 h, and >9 h. Multivariable linear regression models were used to determine the possible association between the night-time sleep duration and HGS. Our results indicated that the shortest (<5 h) or the longest sleep duration (>9 h) was relevant to high risk of weaker HGS in females. In males, the shortest (<5 h) sleep duration was correlated to lower HGS. Thus, our findings clearly suggest that health care providers should focus on the potential influence of sleep duration on HGS among COPD patients.

Determinants of depressive symptom trajectories in self-reported chronic obstructive pulmonary disease patients

BACKGROUND

The depressive symptom trajectories of COPD individuals and its' predictors remain to be established. Therefore, this study aimed to explore the trajectories of depressive symptoms and predictors thereof in COPD patients.

METHODS

A total of 1286 individuals over 45 years of age with self-reported COPD were assessed. Depressive symptoms were evaluated using the Center for Epidemiological Studies Depression Scale short form, with depressive symptom trajectories being identified via latent class growth analysis. The predictors of depressive symptom trajectories were then identified through multinomial logistic regression.

RESULTS

Finally, three depressive symptom trajectories were identified: "steadily high", "consistently moderate", and "consistently low". Old age, longer night-time sleep duration, and high BMI were found to be associated with individuals being classified under the "consistently moderate" trajectory. Moreover, participants exhibiting more than two chronic conditions were more likely to be classified under the "consistently moderate" trajectory. Higher education and lower hand grip strength were important predictors of individuals classified in the "steadily high" trajectory.

CONCLUSIONS

To conclude, three depressive symptom trajectories were identified in self-reported COPD individuals. To ensure timely intervention aimed at preventing the worsening of depressive symptom progression among COPD individuals, health-care workers should regular analyze depressive symptoms and provide appropriate interventions when possible.

Early-Life Exposure to Malnutrition From the Chinese Famine on Risk of Asthma and Chronic Obstructive Pulmonary Disease in Adulthood

Objectives

Intrauterine malnutrition has a long-term effect on respiratory and lung function. However, few studies have explored the association between early-life exposure to famine with asthma and chronic obstructive pulmonary disease (COPD) in adulthood. Therefore, we aimed to investigate the association of early-life exposure to the Chinese famine of 1959–1962 with asthma and COPD later in life.

Methods

This national population-based study included 6,771 participants from the baseline survey of the China Health and Retirement Longitudinal Study (CHARLS) who were born around the time of the Chinese famine. The famine exposure groups were determined according to the participants' birth year as non-exposed (1964–1967), fetal-exposed (1959–1962), preschool-exposed (1954–1957), and school-age exposed (1950–1953). Information about the demographic characteristics, self-reported doctor-diagnosed asthma and COPD, behavior and lifestyles, and indoor pollution were collected using validated questionnaires. In addition, peak expiratory flow (PEF) was measured to assess pulmonary function. Multivariable logistic regression and generalized linear mixed models were performed to explore the risk of adult asthma and COPD, PEF changes during various famine exposure periods compared with the non-exposed group. Stratified and sensitivity analyses were conducted to examine the modification and robustness of the association.

Results

The prevalence of doctor-diagnosed asthma and COPD was 2.8 and 8.1%, respectively. Compared with the non-exposed group, the risk was significantly higher in the fetal-exposed group for asthma [adjusted odds ratio, (aOR) = 1.87, 95% confidence interval (CI):1.14–3.07] and the school-age exposed group [1.30 (1.00–1.69)] for COPD after controlling for confounders. Furthermore, we observed that fetal exposure to famine was significantly associated with a decrement of PEF in adulthood [β = −11.38 (−22.75 to −0.02)] compared with the non-exposed group. Stratified analyses showed that the association of asthma was stronger in men, who resided in severely famine-affected areas, smoked, and used solid fuels for cooking. No clearly consistent association was observed for subsequent COPD.

Conclusions

Our results suggest that fetal exposure to the Chinese famine is significantly associated with the increased risk of asthma in adulthood. Future prospective studies are warranted to examine the association and mechanisms.

Multimorbidity patterns and associated factors in older Chinese: results from the China health and retirement longitudinal study

Background

This study aimed to investigate multimorbidity patterns and their associated factors among elderly population in China.

Methods

A total of 10,479 participants aged at least 60 years were drawn from the 2018 wave of the China Health and Retirement Longitudinal Study (CHARLS). Latent class analysis (LCA) was performed to identify distinct multimorbidity classes based on 14 self-reported chronic conditions. The multinomial logit model was used to analyze the associated factors of multimorbidity patterns, focusing on individuals' demographic characteristics, socioeconomic status (SES), and health behaviors.

Results

Among the 10,479 participants (mean age [SD]: 69.1 [7.1]), 65.6% were identified with multimorbidity. Five multimorbidity clusters were identified by LCA: relatively healthy class (49.8%), vascular class (24.7%), respiratory class (5.6%), stomach-arthritis class (14.5%), and multisystem morbidity class (5.4%). Multinomial logit analysis with the relatively healthy class as the reference showed that participants of older age and female sex were more likely to be in the vascular class and multisystem morbidity class. The probability of being in the vascular class was significantly higher for those with high SES. Ever smoking was associated with a higher probability of being in the respiratory class and multisystem morbidity class. Physical activity was associated with lower odds of being assigned to the vascular class, respiratory class, and multisystem class.

Conclusion

The distinct multimorbidity patterns imply that the prevention and care strategy should target a group of diseases instead of a single condition. Prevention interventions should be paid attention to for individuals with risk factors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-03154-9.

Comparison of Clinical Characteristics and Short-Term Prognoses Within Hospitalized Chronic Obstructive Pulmonary Disease Patients Comorbid With Asthma, Bronchiectasis, and Their Overlaps: Findings From the ACURE Registry

Introduction

Real-world evidence and comparison among commonly seen chronic obstructive pulmonary disease (COPD) phenotypes, i.e., asthma–COPD overlap (ACO), bronchiectasis–COPD overlap (BCO), and their coexistence (ABCO) have not been fully depicted, especially in Chinese patients.

Methods

Data were retrieved from an ongoing nationwide registry in hospitalized patients due to acute exacerbation of COPD in China (ACURE).

Results

Of the eligible 4,813 patients with COPD, 338 (7.02%), 492 (10.22%), and 63 (1.31%) were identified as ACO, BCO, and ABCO phenotypes, respectively. Relatively, the ABCO phenotype had a younger age with a median of 62.99 years [interquartile range (IQR): 55.93–69.48] and the COPD phenotype had an older age with a median of 70.15 years (IQR: 64.37–76.82). The BCO and COPD phenotypes were similar in body mass index with a median of 21.79 kg/m² (IQR: 19.47–23.97) and 21.79 kg/m² (IQR: 19.49–24.22), respectively. The COPD phenotype had more male gender (79.90%) and smokers (71.12%) with a longer history of smoking (median: 32.45 years, IQR: 0.00–43.91). The ACO and ABCO phenotypes suffered more prior allergic episodes with a proportion of 18.05 and 19.05%, respectively. The ACO phenotype exhibited a higher level of eosinophil and better lung reversibility. Moreover, the four phenotypes showed no significant difference neither in all-cause mortality, intensive care unit admission, length of hospital stay, and COPD Assessment Test score change during the index hospitalization, and nor in the day 30 outcomes, i.e., all-cause mortality, recurrence of exacerbation, all-cause, and exacerbation-related readmission.

Conclusions

The ACO, BCO, ABCO, and COPD phenotypes exhibited distinct clinical features but had no varied short-term prognoses. Further validation in a larger sample is warranted.

Prevalence of and risk factors for asthma among people aged 45 and older in China: a cross-sectional study

Background

Asthma is one of the most prevalent chronic respiratory diseases worldwide. This study aimed to determine the updated prevalence of and risk factors for asthma among individuals aged 45 and older in mainland China.

Methods

The data for this study came from the fourth wave of the China Health and Retirement Longitudinal Study (CHARLS) conducted by the National School of Development of Peking University in 2018. The CHARLS is a nationally representative survey targeting populations aged 45 and over from 28 provinces/cities in mainland China. A representative sample of 19,816 participants was recruited for the study using a multistage stratified sampling method. The prevalence of asthma was determined across different characteristics. The potential risk factors were examined by multivariable logistic regressions.

Results

A total of 18,395 participants (8744 men and 9651 women) were eligible for the final data analysis. The estimated prevalence of asthma among Chinese people aged ≥ 45 years in 2018 was 2.16% (95% CI 1.96–2.38). The prevalence of asthma significantly differed according to race (P = 0.002), with an overall rate of 2.07% (95% CI 1.86–2.29) in Han paticipants and 3.32% (95% CI 2.50–4.38) in minority participants. Furthermore, the minority ethnicities (OR = 1.55 [95% CI 1.12–2.14], P = 0.008), older age (60–69 years group: OR = 1.85 [95% CI 1.17–2.92], P = 0.008; ≥ 70 years group: OR = 2.63 [95% CI 1.66–4.17], P < 0.001), an education level of middle school or below (middle-school education: OR = 1.88 [95% CI 1.15–3.05], P = 0.011; primary education: OR = 2.48 [95% CI 1.55–3.98], P < 0.001; literate: OR = 2.53 [95% Cl 1.57–4.07], P < 0.001; illiterate: OR = 2.78 [95% CI 1.72–4.49, P < 0.001]), smoking (OR = 1.37 [95% CI 1.11–1.68], P = 0.003), and residence in North (OR = 1.52 [95% CI 1.11–2.09], P = 0.01) or Northwest China (OR = 1.71 [95% CI 1.18–2.49], P = 0.005) were associated with prevalent asthma.

Conclusions

Asthma is prevalent but underappreciated among middle-aged and elderly people in China. A number of risk factors were identified. These results can help to formulate correct prevention and treatment measures for asthma patients.

Reference Values and Related Factors for Peak Expiratory Flow in Middle-Aged and Elderly Chinese

Background: Peak expiratory flow (PEF), as an essential index used for screening and monitoring asthma, chronic obstructive pulmonary disease, and respiratory mortality especially in the elderly, is recommended for low-resource settings in low- and middle-income countries. However, few studies have focused on the reference of PEF in China, especially in middle-aged and elderly people. Thus, this study aimed to determine age- and sex-specific reference values of PEF in the middle-aged and elderly Chinese population. Methods: There were 8,914 participants who were included for risk factor analysis and 5,498 participants included for reference value analysis. The PEF was measured using a peak flow meter in liters per minute. The distributions of standardized PEF terciles stratified by sex and age were reported. Multiple linear regression analysis was used to determine the associations between risk factors and PEF. Results: The PEF was higher in men than women across all age subgroups. The value of PEF decreased with age in both men and women. Height, weight, handgrip strength, and residence in rural were positively associated with PEF. Age and smoking status were negatively associated with PEF significantly in both men and women (P < 0.05). The mean PEF values were 367.10 and 253.00 L/min for men and women, respectively. Meanwhile, the prevalence of low PEF was 3.94 and 3.32% for men and women, respectively. Conclusions: Age- and sex-specific centiles of standardized PEF for the middle-aged and elderly Chinese population were estimated. The reference values for low PEF could provide reference standards for epidemiological studies and clinical practices in the future. Interventions to improve lung functions or to prevent respiratory disease should be paid more attention to factors associated with PEF.

Determinants of Self-Rated Health Among Middle-Aged and Elderly Patients with COPD: The China Health and Retirement Longitudinal Study

This study aimed to assess self-rated health (SRH) status and its determinants in patients with chronic obstructive pulmonary disease (COPD). Participants aged at least 45 years were included from a nationally representative investigation in 2015. The SRH assessment was divided into two groups: "good" and "not good." Independent samples t-tests, chi-square tests, and Fisher's exact tests were used to determine differences in patient characteristics between the two groups. Multiple logistic models were used to determine factors influencing SRH. A total of 1,215 patients with COPD were included in the final analysis, of whom 21.2% reported favorable SRH status. The results indicated that female gender, non-smoking, and elevated peak expiratory flow correlated with better SRH, while nighttime sleep duration less than 7 hours, asthma, and disability, negatively impacted SRH. Our findings provide new evidence for the development of effective health promotion programs for the well-being of patients with COPD.

Serum Magnesium and Fractional Exhaled Nitric Oxide in Relation to the Severity in Asthma-Chronic Obstructive Pulmonary Disease Overlap

Serum concentrations of magnesium and manganese may be associated with increased chronic obstructive pulmonary disease exacerbation risk. However, associations with other aspects of asthma-chronic obstructive pulmonary disease overlap, pulmonary function test results and health status, have been studied less extensively. The aim of this study was to investigate the associations between serum concentrations of trace elements and T lymphocyte subsets, FeNO, and COPD-related questionnaire scores in individuals with ACO and the potential impact of these parameters on lung function. All the patients met the diagnostic criteria of ACO and were divided into two groups (group A, mild-moderate; group B, severe-very severe) by their specific characteristics. Pulmonary function testing and serum Mg and serum Mn and FeNO were measured. Four hundred sixty-five patients were screened, and 42 were included. Group A had significantly higher Mg and Fe concentrations than group B. No significant differences were seen in the serum concentration of any other trace element between the two groups. Serum Mg and Mn were correlated with FEV1% predicted (p < 0.01). Group A had a significantly higher FeNO concentration than group B (p = 0.005). The scores on CAT (p = 0.011) and mMRC (p = 0.008) in group A were lower than in group B. The low-FeNO group had a significantly lower concentration of serum Mg than the high-FeNO group (p = 0.03). Pulmonary function declined faster (p < 0.05) in the low-FeNO group than the high-FeNO group. Serum Mg concentration may indicate protective effects against lung function loss in ACO. This implies that FeNO might be a biomarker for identifying individuals with ACO who might benefit from inhaled corticosteroid therapy. Serum Mg and FeNO were associated with ACO severity. However, their role in guiding personalised treatment of individuals with ACO needs to be further investigated.

Asthma-Chronic Obstructive Pulmonary Disease Overlap

Asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO) defines a subgroup of patients with asthma who have persistent airflow obstruction or patients with COPD who may exhibit variable airflow limitation and/or evidence of type 2 inflammation. Additional investigations are needed to determine whether ACO represents a distinct disorder with unique underlying pathophysiology, whether ACO patients should be managed differently from those with asthma or COPD, and whether the diagnosis affects long-term outcomes. This article presents the data about the clinical features of ACO, the current information regarding the underlying pathophysiology of the syndrome, and current understanding of therapeutic options.