Chronic obstructive pulmonary disease and cognitive impairment in the Chinese elderly population: a large national survey

Trajectories of health conditions and their associations with the risk of cognitive impairment among older adults: insights from a national prospective cohort study

BACKGROUND

The associations between trajectories of different health conditions and cognitive impairment among older adults were unknown. Our cohort study aimed to investigate the impact of various trajectories, including sleep disturbances, depressive symptoms, functional limitations, and multimorbidity, on the subsequent risk of cognitive impairment.

METHODS

We conducted a prospective cohort study by using eight waves of national data from the Health and Retirement Study (HRS 2002-2018), involving 4319 adults aged 60 years or older in the USA. Sleep disturbances and depressive symptoms were measured using the Jenkins Sleep Scale and the Centers for Epidemiologic Research Depression (CES-D) scale, respectively. Functional limitations were assessed using activities of daily living (ADLs) and instrumental activities of daily living (IADLs), respectively. Multimorbidity status was assessed by self-reporting physician-diagnosed diseases. We identified 8-year trajectories at four examinations from 2002 to 2010 using latent class trajectory modeling. We screened participants for cognitive impairment using the 27-point HRS cognitive scale from 2010 to 2018 across four subsequent waves. We calculated hazard ratios (HR) using Cox proportional hazard models.

RESULTS

During 25,914 person-years, 1230 participants developed cognitive impairment. In the fully adjusted model 3, the trajectories of sleep disturbances and ADLs limitations were not associated with the risk of cognitive impairment. Compared to the low trajectory, we found that the increasing trajectory of depressive symptoms (HR = 1.39; 95% CI = 1.17-1.65), the increasing trajectory of IADLs limitations (HR = 1.88; 95% CI = 1.43-2.46), and the high trajectory of multimorbidity status (HR = 1.48; 95% CI = 1.16-1.88) all posed an elevated risk of cognitive impairment. The increasing trajectory of IADLs limitations was associated with a higher risk of cognitive impairment among older adults living in urban areas (HR = 2.30; 95% CI = 1.65-3.21) and those who smoked (HR = 2.77; 95% CI = 1.91-4.02) (all P for interaction < 0.05).

CONCLUSIONS

The results suggest that tracking trajectories of depressive symptoms, instrumental functioning limitations, and multimorbidity status may be a potential and feasible screening method for identifying older adults at risk of cognitive impairment.

COPD, Dietary Fiber Intake, and Cognitive Performance in Older Adults: A Cross-Sectional Study from NHANES 2011-2014

INTRODUCTION

This study aimed to evaluate the modifying role of dietary fiber intake in the relationship between COPD and cognitive performance.

METHODS

Data of adults aged ≥60 years were extracted from the National Health and Nutrition Examination Survey (NHANES) 2011-2014. Participants with information on cognitive function measures were included. Dietary fiber intake, identified using participants' 24-h recall surveys, was grouped into high (>25 g/day) and low (≤25 g/day) levels. COPD was identified through self-reported physician diagnoses. Associations between dietary fiber intake, cognitive function and COPD were evaluated using the regression analysis.

RESULTS

Data of 2,189 participants were analyzed. Multivariate analysis revealed that COPD was significantly associated with lowered CERAD (adjusted beta [aBeta]: -0.17, 95% confidence interval [CI]: -0.33 to -0.002, p = .047) and DSST (aBeta: -2.23, 95% CI: -4.25 to -0.2, p = .032) scores in older adults. The analysis on the association between COPD and cognitive function stratified by dietary fiber intake revealed that COPD remained significantly associated with lowered CREAD among individuals with a high fiber intake (aBeta: -0.54, 95% CI: -1.00 to -0.08, p = .024).

CONCLUSIONS

In US older adults, COPD is associated with reduced cognitive function. However, the findings do not support that high dietary fiber intake may modify the association between COPD and cognitive impairment.

Rural-Urban Differences in Mild Cognitive Impairment Among Patients with Chronic Obstructive Pulmonary Disease in ChengDu, China

Purpose

The rural-urban gap in sociodemographic, lifestyle, and disease-related characteristics among COPD patients is prevalent. These differences may influence the prevalence of mild cognitive impairment (MCI). This study aimed to compare the prevalence and determinants of MCI between rural and urban areas among COPD patients.

Patients and Methods

The cross-sectional study sample comprised 372 COPD patients from China. We evaluated the cognitive function and lung function, collected sociodemographic, lifestyle, and disease-related information, to compare the prevalence of MCI in rural and urban areas. Using multivariate regression analysis to examine the effects of variables to MCI.

Results

The prevalence of MCI in rural areas was higher than that in urban areas (65.4% vs 47.9%, P=0.001). The prevalence in farm laborers was almost twice as high as that of non-farm laborers in urban areas (82.6% vs 43.1%), but no significant difference in rural areas (P=0.066). However, the data were lower in subjects who insisted on long-term home oxygen therapy (39.7%, CI:27.8-51.6, P<0.001), and who with higher monthly household income (49.6%, CI:40.2-58.9) in rural areas, but no significant difference in urban areas (P=0.985 and 0.502). Multivariate logistic regression analysis indicated that participants aged 71 years and above, former smokers were at a high risk of MCI in both urban and rural areas. However, participants who slept for 6-8 hours a day, shopping frequently, or exercised for more than 2 hours a day had a lower risk of MCI in urban areas. But rural participants who insisted on long-term home oxygen therapy had a lower probability of developing MCI.

Conclusion

This study revealed that there were significant differences in MCI among COPD patients in rural and urban areas, especially in exercise, sleeping, shopping, and long-term home oxygen therapy. Medical staff should give health guidance according to the actual situation of patients with COPD.

Mediating role of depressive symptoms on the relationship between sleep duration and cognitive function

Although some studies have shown the association between sleep duration and cognitive impairment is positive, the mechanism explaining how sleep duration is linked to cognition remains poor understood. The current study aims to explore it among Chinese population. A cross-sectional study of 12,589 participants aged 45 or over was conducted, cognition was assessed by three measures to capture mental intactness, episodic memory, and visuospatial abilities. The Center for Epidemiologic Studies Depression Scale 10 (CES-D₁₀) was administered during the face-to-face survey to assess depressive status. Sleep duration was reported by the participants themselves. Partial correlation and linear regression were used to explore the association between sleep duration, cognition, and depression. The Bootstrap methods PROCESS program was used to detect the mediation effect of depression. Sleep duration was positively correlated with cognition and negatively with depression (p < 0.01). The CES-D₁₀ score (r = - 0.13, p < 0.01) was negatively correlated with cognitive function. Linear regression analysis showed sleep duration was positively associated with cognition (p = 0.001). When depressive symptoms were considered, the association between sleep duration and cognition lost significance (p = 0.468). Depressive symptoms have mediated the relationship between sleep duration and cognitive function. The findings revealed that the relationship between sleep duration and cognition is mainly explained by depressive symptoms and may provide new ideas for interventions for cognitive dysfunction.

Multidimensional healthy life expectancy of the older population in China

Research on healthy life expectancy (HLE) that considers cognitive impairment has been inadequate, particularly in the context of less developed countries. Using data from the China Health and Retirement Longitudinal Study, our study fills this research gap by computing active life expectancy (ALE), cognitive-impairment-free life expectancy (CIFLE), and active and cognitive-impairment-free life expectancy (ACIFLE) for China's older population, using multistate life tables. Results show that at age 60, the three life expectancies were 19.4 years (ALE), 9.5 years (CIFLE), and 8.8 years (ACIFLE) during the period 2011-13. HLE exhibits significant differentials by sex, urban/rural residence, educational level, marital status, and health status at age 60. Among China's older people, males and those living in urban areas experience higher CIFLE, and those who live with a spouse, are more educated, and are healthy at age 60 expect more years in good health according to all three HLE measures.Supplementary material for this article is available at: https://doi.org/10.1080/00324728.2021.1914854.

Association between biomass fuel use and the risk of cognitive impairment among older populations in China: a population-based cohort study

BACKGROUND

Cohort studies on the impact of biomass fuel use for cooking on cognitive impairment among older population are still lacking in China and elsewhere. The aim of this study was to examine whether biomass fuel use for cooking is associated with cognitive impairment in Chinese adults aged 65 years or older.

METHODS

The prospective population-based cohort study of the Chinese Longitudinal Healthy Longevity Survey (CLHLS) included participants aged 65 years or older in 2014 who were followed-up until 2018 in 23 provinces in China. The Mini-Mental State Examination (MMSE) was used to assess cognitive function, and cognitive impairment was defined as total MMSE scores less than 18. The association between biomass fuel use and cognitive impairment was evaluated using the Cox proportional hazards model.

RESULTS

Of the 4145 participants included at baseline, participants who reported that they used biomass fuel for cooking (40.43%; IR: 3.11 versus 2.77 per 100 person-years; aHR: 1.27, 95% CI: 1.02-1.58) had a higher risk of cognitive impairment compared with participants who used clean fuels (53.75%). A stratified analyses showed greater effect estimates of cognitive impairment in the older people that lived in the rural areas (aHR: 1.444, 95% CI: 1.08-3.90) and never smoked (aHR: 1.33, 95% CI: 1.04-1.71).

CONCLUSIONS

These findings demonstrated that biomass fuel used for cooking was associated with cognitive impairment, as defined by MMSE, in a population-based study of elderly in China. To prevent cognitive impairment, the structure of cooking fuels requires improvements.

The effects of indoor air pollution from solid fuel use on cognitive function among middle-aged and older population in China

OBJECTIVES

Growing evidence has linked outdoor air pollution exposure with higher risk of cognitive impairments. However, the role of indoor air pollution in cognitive decline is not well elaborated. By using nationally representative longitudinal data, this study aimed to explore the effects of indoor air pollution from solid fuel use on cognitive function among middle-aged and older individuals in China.

METHODS

Data were obtained from 2011 to 2015 waves of CHARLS (China Health and Retirement Longitudinal Study). Scores from the Telephone Interview of Cognitive Status and figure drawing/word recall tests were used to measure cognitive function in 39,482 individuals. Exposure to indoor air pollution was measured as use of solid fuel for cooking. Solid fuel was defined as coal, biomass charcoal, wood, and straw; clean fuel was defined as liquefied gas, natural gas, and electricity. Linear mixed effect models were applied to examine the effect of indoor air pollution from solid fuel use on cognitive function.

RESULTS

Participants had an average global cognitive function of 9.67 (SD = 4.13). Solid fuel users made up 49.71% of participants, but this proportion was much greater among those living in rural areas (64.22%). Compared with clean fuel users, solid fuel users had worse cognitive function. On average, solid fuel users had a 0.81 (95%CI: -0.89, -0.73) lower global cognition score, 0.63 (95%CI: -0.69, -0.57) lower mental health score, and 0.16 (95%CI: -0.22, -0.14) lower episodic memory score. These effects were stronger among participants who are female, aged 65 years old and above, have education level of primary school and below, or have cardiovascular diseases.

CONCLUSIONS

These results provide evidence for the role of indoor air pollution in neurobehavioral disorders in China. Promotion of practices like expanded use of clean fuel and improved stoves in households may be crucial to significantly reduce indoor air pollution and protect mental health.

Impact of secondhand smoke exposure on cognitive function among middle-aged and older women in China: findings from three waves of the China Health and Retirement Longitudinal Study

OBJECTIVES

To examine the association between secondhand smoke (SSH) and women's global cognitive function and cognitive subdomains.

DESIGN

Cohort study.

PARTICIPANTS

Data for this study were obtained from the China Health and Retirement Longitudinal Study (2011-2013-2015), and pooled analysis was applied to wave 1 and wave 2 (2011-2013), wave 2 and wave 3 (2013-2015) and wave 1 and wave 3 (2011-2015). Data from a total of 6875 Chinese women with normal cognitive function at baseline were selected for analysis, including 2981 who were interviewed in 2011, 2471 in 2013, and 1894 in 2015.

MAIN OUTCOME MEASURES AND METHODS

SHS was classified based on the number of exposed years (<25 years, ≥25 years to <30 years, ≥30 years to <40 years, ≥40 years). Global cognitive function, visuospatial ability, orientation and attention, and episodic memory function were used as measures of cognitive function. Three waves of data were pooled using a dummy variable to differentiate between 2-year and 4-year groups. LDV models were used to examine independent associations between SHS and cognitive function. Demographic factors, socioeconomic factors, baseline cognitive functioning and health conditions were controlled for in our models.

RESULTS

SSH was found to be inversely and significantly associated with cognitive function. Compared with those who had not been exposed to household SSH, women who had lived with a smoking husband had a significantly faster cognition decline, especially in global cognitive function (β=-0.33, 95% CI=-0.66 to -0.01, p<0.01), visuospatial ability (β=-0.04, 95% CI=-0.08 to -0.01, p<0.05) and episodic memory function (β=-0.16, 95% CI=-0.31 to -0.01, p=0.031).

CONCLUSIONS

Household SSH exposure for more than 40 years was associated with a more significant decline in global cognitive function, visuospatial ability and episodic memory function, but not in orientation and attention function among older Chinese women.

Severe obstructive sleep apnea in patients with chronic obstructive pulmonary disease is associated with an increased prevalence of mild cognitive impairment

BACKGROUND

Chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) are associated with mild cognitive impairment (MCI). However, this association is unclear. This study aimed to assess the prevalence of MCI in patients with overlap syndrome, determine whether OSA increases the risk of MCI in patients with COPD, and investigate the potential mechanisms for this association.

METHODS

Participants with stable Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage 2-4 COPD and complaints of snoring in 2016-2018 were enrolled in this cross-sectional observational study. All were free of asthma, acute left-sided congestive heart failure, unstable coronary heart disease, uncontrolled hypertension, diabetes, encephalitis, and epilepsy. They underwent pulmonary function tests and overnight polysomnography and completed the Montreal Cognitive Assessment (MoCA). MCI was defined by an MoCA score of <23, while OSA was defined by an apnea-hypopnea index (AHI) of ≥15 per hour. The association between MCI, demographics, and comorbidities was tested by logistic regression analysis with adjustment for confounders. Sleep-disordered breathing measures were investigated as potential mechanisms underlying this relationship.

RESULTS

MCI was significantly more common in patients with overlap syndrome than in those with COPD (40.6% [43/106] vs 24.6% [42/171]). After adjustment, severe OSA was an independent contributor to MCI (odds ratio, OR 2.27; 95% confidence interval, CI 1.12-4.62). Increased percent of night-time spent with oxygen saturation <90% (TSat₉₀) was associated with increased odds of MCI (odds ratio 4.75, 95% CI 2.73-11.13).

CONCLUSIONS

MCI is more prevalent in overlap syndrome than in COPD. OSA may contribute to MCI in COPD. The mechanism may involve TSat₉₀.

Patterns of brain structural alteration in COPD with different levels of pulmonary function impairment and its association with cognitive deficits

Background

To explore patterns of brain structural alteration in chronic obstructive pulmonary disease (COPD) patients with different levels of lung function impairment and the associations of those patterns with cognitive functional deficits using voxel-based morphometry (VBM) and tract-based spatial statistics (TBSS) analyses based on high-resolution structural MRI and diffusion tensor imaging (DTI).

Methods

A total of 115 right-handed participants (26 severe, 29 moderate, and 29 mild COPD patients and a comparison group of 31 individuals without COPD) completed tests of cognitive (Montreal Cognitive Assessment [MoCA]) and pulmonary function (forced expiratory volume in 1 s [FEV1]) and underwent MRI scanning. VBM and TBSS analyses were used to identify changes in grey matter density (GMD) and white matter (WM) integrity in COPD patients. In addition, correlation analyses between these imaging parameter changes and cognitive and pulmonary functional impairments were performed.

Results

There was no significant difference in brain structure between the comparison groups and the mild COPD patients. Patients with moderate COPD had atrophy of the left middle frontal gyrus and right opercular part/triangular part of the inferior frontal gyrus, and WM changes were present mainly in the superior and posterior corona radiata, corpus callosum and cingulum. Patients with severe COPD exhibited the most extensive changes in GMD and WM. Some grey matter (GM) and WM changes were correlated with MoCA scores and FEV1.

Conclusions

These findings suggest that patients with COPD exhibit progressive structural impairments in both the GM and the WM, along with impaired levels of lung function, highlighting the importance of early clinical interventions.

Non-communicable Diseases and Cognitive Impairment: Pathways and Shared Behavioral Risk Factors Among Older Chinese

Population aging has brought about a number of challenges to public health and primary health care systems due to increases in the prevalence of non-communicable diseases (NCDs). As a country with one of the largest populations globally, China is confronting a rising number of chronic NCDs including cardiometabolic related conditions. This mini-review investigates the link between NCDs and cognitive impairment through common risk factors. Identifying risk factors is important for the prevention and management of these chronic conditions. In addition, this review also identifies the role of primary health care services in reducing behavioral risk factors for NCDs and cognitive impairment. Addressing shared determinants and pathways is important in the design of public health interventions and primary health care services in China. Monitoring and management of NCD biomarkers and behavioral risk factors may also be beneficial for cognitive health among older Chinese.

Association between chronic obstructive pulmonary disease and activity of daily living among oldest-old in China: based on Chinese Longitudinal Health Longevity Survey

Aims

This study was designed to investigate the association between COPD and activity of daily living among oldest-old in People's Republic of China.

Patients and methods

The data of Chinese Longitudinal and Health Longevity Study in 2014 was used, and those who were aged more than 80 years old were included. Both basic activity of daily living (BADL) and instrumental activity of daily living (IADL) were measured.

Results

A total of 4621 oldest-old (≥80 years old) were included. 32.1% (1482) of the oldest-old had BADL disability and 79.0% (3129) had IADL disability. The BADL disability and IADL disability rates were higher for participants with COPD than those without, and this difference was more robust among male (31.8% vs 25.6%, p=0.018). The IADL disability rate showed similar trends. Multivariate logistic regression analysis showed that the odds ratios of COPD on BADL disability and IADL disability were 1.261 (95% CI: 1.044–1.525) and 2.014 (95% CI: 1.561–2.598), respectively. The odds ratios of COPD on moderate to severe BADL disability and IADL disability were 1.007 (95% CI: 0.790–1.284) and 1.713 (95% CI: 1.397–2.100), respectively.

Conclusion

There were independent associations between COPD and disability among oldest-old in People's Republic of China, and the associations were greater among male population. Besides, COPD had a profound influence on the mild disability of BADL, while had a greater impact on the moderate and severe disability of IADL.

Secondhand Smoke and Women's Cognitive Function in China

Exposure to secondhand smoke (SHS) is known to be harmful to health. However, the association between household SHS and cognitive function among middle-aged and older women in China is understudied. Lagged dependent variable regression was used to examine the association between household SHS exposure and the cognitive function of married women who had been exposed to SHS, using data from 2 waves of the China Health and Retirement Longitudinal Study (CHARLS, 2011-2013). Controlling for age, educational attainment, geographic residence, household expenditures, and chronic conditions (i.e., hypertension, diabetes, and depressive symptoms), the results indicated that longer SHS exposure was associated with a greater decline in memory over 2 years. After comparing differences across age groups, this pattern was significant for women aged 55-64 years. Furthermore, those who were illiterate, lived in rural areas, and reported depressive symptoms had a greater decline in memory. With evidence linking household SHS exposure with a higher risk of cognitive decline, effective education and public health intervention programs are urgently needed. Stronger tobacco control regulations and education about the dangers of household SHS are viable strategies to reduce the impending dementia epidemic in China.

The effects of depression, anxiety and sleep disturbances on cognitive impairment in patients with chronic obstructive pulmonary disease

The purpose of this study was to investigate the effects of depression, anxiety and sleep disturbances on cognitive functions in chronic obstructive pulmonary disease (COPD) patients. In this prospective case-control study, demographic data, smoking history, depression, anxiety, sleep quality and cognitive status of 48 COPD patients and 36 healthy volunteers aged 40-90 years were recorded. The Beck depression inventory (BDI), the Beck anxiety inventory (BAI), and Pittsburgh Sleep Quality Index (PSQI) were used to assess depression, anxiety and sleep quality, respectively in COPD patients. Cognitive performance was studied by the mini-mental state examination. The mean age of patients with COPD was 65.3 ± 9.4 years, and disease duration was 9.6 ± 7.8 years. Male sex ratio, smoking, BDI score, BAI score, total PSQI score, sleep latency, sleep duration, average use of sleep aids and sleep disturbances in patients with COPD were significantly higher than the control group (p < 0.05). When cognitive impairment was compared by age, FVC, FEV, FEV/FVC, PEF values and smoking, no statistically significant relationship was found (p > 0.05). A statistically significant relationship was established between cognitive impairment and severity of disease, presence of anxiety, presence of depression and sleep quality. In our study, we found that sleep disorders, depression and anxiety comorbid with COPD increased cognitive impairment as well as the severity of disease. We believe that this finding is important in terms of reducing the risk of cognitive impairment, preventing misdiagnosis and treatment of the aforementioned comorbid diseases.

Perception of symptoms and quality of life - comparison of patients' and physicians' views in the COPD MIRROR study

OBJECTIVES

The aim of this study was to compare potential differences between the perception that COPD patients have of their disease and the perception that physicians have of how the disease affects their patients.

METHODS

Surveys in COPD patients and physicians caring for COPD patients were conducted in Spain, Italy, and Germany. Online questionnaires mirrored to explore the same domains, were administered to patients and physicians. Physicians were asked to respond to the questionnaire taking a recently seen patient who represents the majority of COPD patients usually managed, as a reference. Patients with COPD completed a survey containing the same questions offered to the physicians (Medical Investigation of Respiratory COPD Perception [MIRROR] survey). Comparisons between the responses of patients and general practitioners (GPs) and between patients and pulmonologists (PULs) were run separately using the chi-square, Fisher's exact, or Student's t-tests.

RESULTS

A total of 334 COPD patients, 333 GPs, and 333 PULs participated in the surveys. The typical perception that PULs have of the COPD patient was that of an older man with more severe disease and less likely to be a smoker, than the included COPD patients. COPD was regarded as a major health problem by patients and physicians, but its impact on overall quality of life among more severe patients was less strongly perceived by physicians than by patients. Instead, physicians paid more attention to domains related to clinical features (cough, phlegm, and dyspnea), while underestimating COPD impact on leisure and social activities. The majority of patients stated not being completely frank with their doctors during visits. Both GPs and PULs seemed to recognize this issue but underestimated its extent.

CONCLUSION

To improve the doctor-patient communication, a more frank reporting by the patients of their symptoms and feelings and an increased awareness of physicians about the impact on nonconventional domains that patients perceive as importantly affected by COPD should be encouraged.