From Mild Cognitive Impairment (MCI) to Dementia in Chronic Obstructive Pulmonary Disease. Implications for Clinical Practice and Disease Management: A Mini-Review

The Impact of Pulmonary Disorders on Neurological Health (Lung-Brain Axis)

The brain and lungs, vital organs in the body, play essential roles in maintaining overall well-being and survival. These organs interact through complex and sophisticated bi-directional pathways known as the 'lung-brain axis', facilitated by their close proximity and neural connections. Numerous studies have underscored the mediation of the lung-brain axis by inflammatory responses and hypoxia-induced damage, which are pivotal to the progression of both pulmonary and neurological diseases. This review aims to delve into how pulmonary diseases, including acute/chronic airway diseases and pulmonary conditions, can instigate neurological disorders such as stroke, Alzheimer's disease, and Parkinson's disease. Additionally, we highlight the emerging research on the lung microbiome which, drawing parallels between the gut and lungs in terms of microbiome contents, may play a significant role in modulating brain health. Ultimately, this review paves the way for exciting avenues of future research and therapeutics in addressing respiratory and neurological diseases.

Association between dietary supplement use and mortality in cancer survivors with different body mass index and frailty status: a cohort study

Background

The association between Body Mass Index (BMI), frailty index (FI), and dietary supplement in cancer survivors has been a subject of growing interest. This study investigates the relationship of BMI and FI with mortality in American cancer survivors and explores the impact of dietary supplement usage on different BMI and FI groups.

Methods

Three thousand nine hundred and thirty-two cancer patients from the National Health and Nutrition Examination Survey (NHANES) database were included in the analyses. BMI, FI, and supplement usage were obtained through the NHANES structured survey and the 49-item FI tool. Weighted logistic and Cox proportional hazards models, Kaplan-Meier survival analyses, and propensity score matching (PSM) were used to elucidate the relationships between BMI, FI, dietary supplement, and mortality outcomes.

Results

The study found significant associations between higher BMI and increased frailty (Odds ratio [OR] = 1.04, 95% confidence interval [95% CI], 1.02-1.06). BMI < 25 kg/m2 and FI > 0.2 are associated with an increased mortality rate. Dietary supplement use can reduce all-cause and cancer mortality in cancer patients with BMI < 25 kg/m2 (Hazard ratio [HR] = 0.63, 95% CI, 0.47-0.84; HR = 0.48, 95% CI, 0.29-0.80) or FI ≤ 0.2 (HR = 0.77, 95% CI, 0.60-0.99; HR = 0.59, 95% CI, 0.39-0.89). In cancer patients with BMI < 25 kg/m2 and FI ≤ 0.2, dietary supplement users had lower all-cause and cancer mortality (HR = 0.49, 95% CI, 0.30-0.79; HR = 0.25, 95% CI, 0.10-0.60).

Conclusion

The study revealed a negative correlation between BMI and the FI among the cancer patient cohort as well as their complex impact on mortality and highlighted the role of dietary supplement in cancer prognosis, indicating benefits for non-frail patients with BMI < 25 kg/m2.

Effect of individualized PEEP titration by ultrasonography on perioperative pulmonary protection and postoperative cognitive function in patients with chronic obstructive pulmonary disease

OBJECTIVE

To evaluate the effect of the individualized positive end-expiratory pressure (PEEP) lung protection ventilation strategy by combining driving pressure (ΔP) and pulmonary ultrasound (LUS)-based titration on lung function and postoperative cognitive function in patients with chronic obstructive pulmonary disease (COPD) during laparoscopic surgery.

METHODS

A total of 108 patients with COPD undergoing laparoscopic gastrointestinal surgery under general anesthesia were included in this study. They were randomly divided into three groups (n = 36): traditional volume ventilation group (Group C), fixed PEEP 5 cmH₂O group (Group P), and ΔP combined with LUS-based PEEP titration in the resuscitation room group (Group T). All three groups were given volume ventilation mode, I:E = 1:2; In group C, VT was 10 mL/kg and PEEP was 0 cmH₂O; In groups P and T, VT was 6 mL/kg and PEEP was 5 cmH₂O; After mechanical ventilation for 15 min in Group T, ΔP in combination with LUS was used to titrate PEEP. The oxygenation index (PaO2/FiO2), airway platform pressure (Pplat), dynamic lung compliance (Cdyn), Montreal Cognitive Assessment (MoCA), and venous interleukin-6(IL-6) were recorded at the corresponding time points, and the final PEEP value in Group T was recorded.

RESULTS

The final PEEP value of Group T was (6.4 ± 1.2) cmH₂O; Compared with groups C and P: PaO₂/FiO₂ and Cdyn in Group T were significantly increased (P < 0.05) and value of IL-6 was significantly decreased (P < 0.05) at the corresponding time points. Compared with group C, the MoCA score on day 7 after surgery in Group T was significantly higher (P < 0.05).

CONCLUSION

Compared with the traditional ventilation strategy, the individualized ΔP combined with LUS-based PEEP titration in patients with COPD during the perioperative period of laparoscopic surgery can play a better role in lung protection and can improve postoperative cognitive function.

Cognitive decline and risk of dementia in older adults after diagnosis of chronic obstructive pulmonary disease

Cognitive screening has been proposed for older adults diagnosed with chronic obstructive pulmonary disease (COPD). Therefore, we examined the change over time in cognitive function and the risk of incident dementia in older adults after COPD diagnosis. A sample of 3,982 participants from the population-based cohort study Good Aging in Skåne was followed for 19 years, and 317 incident COPD cases were identified. The cognitive domains of episodic memory, executive function, and language were assessed using neuropsychological tests. Mixed models for repeated measures and a Cox model were implemented. Participants performed, on average, worse over time on all neuropsychological tests after COPD diagnosis in comparison to those without COPD, although statistical significance differences were only observed for episodic memory and language. The groups had a comparable risk of developing dementia. In conclusion, our results indicate that cognitive screening in the early stages of COPD may be of limited clinical relevance.

The adjusted impact of different severities of acute exacerbations and medications on the risk of developing dementia in COPD patients

BACKGROUND

Although a relationship between chronic obstructive pulmonary disease (COPD) and dementia has been reported, the initial severity upon emergency department (ED) visits and the medications used have not been well evaluated as risk factors for increased dementia occurrence. We aimed to analyze the risks of dementia development over 5 years among patients with COPD compared to matched controls (primary) and the impact of different severities of acute exacerbations (AEs) of COPD and medications on the risk of dementia development among COPD patients (secondary).

METHOD

This study used the Taiwanese government deidentified health care database. We enrolled patients during the 10-year study period (January 1, 2000, to December 31, 2010), and each patient was followed up for 5 years. Once these patients received a diagnosis of dementia or died, they were no longer followed up. The study group included 51,318 patients who were diagnosed with COPD and 51,318 matched (in terms of age, sex, and the number of hospital visits) non-COPD patients from the remaining patients as the control group. Each patient was followed up for 5 years to analyze the risk of dementia with Cox regression analysis. Data on medications (antibiotics, bronchodilators, corticosteroids) and severity at the initial ED visit (ED treatment only, hospital admission, or ICU admission) were collected for both groups, as well as demographics and baseline comorbidities, which were considered confounding factors.

RESULTS

In the study and control groups, 1,025 (2.0%) and 423 (0.8%) patients suffered from dementia, respectively. The unadjusted HR for dementia was 2.51 (95% CI: 2.24-2.81) in the study group. Bronchodilator treatment was associated with the HRs, especially among those who received long-term (> 1 month) treatment (HR = 2.10, 95% CI: 1.91-2.45). Furthermore, among 3,451 AE of COPD patients who initially visited the ED, patients who required ICU admission (n = 164, 4.7%) had a higher risk of dementia occurrence (HR = 11.05, 95% CI: 7.77-15.71).

CONCLUSION

Bronchodilator administration might be associated with a decreased risk of dementia development. More importantly, patients who suffered AEs of COPD and initially visited the ED and required ICU admission had a higher risk of developing dementia.

Asthma, the central nervous system, and neurocognition: Current findings, potential mechanisms, and treatment implications

Accumulating behavioral evidence suggests that asthma is associated with cognitive deficits. A number of studies have identified potential biological contributions to cognition in asthma; however, mechanistic pathways of central nervous system (CNS) involvement in asthma are yet to be established. We therefore conducted a literature review to identify studies examining potential CNS contributions to cognition in asthma. In this review, we discuss our general understanding of the CNS in asthma in the context of cognitive performance and outline a working model of mechanistic pathways linking the proposed neural influences of asthma pathology with cognition. To this extent, we incorporate neural, behavioral, psychological, social and environmental factors. Finally, we underscore the clinical significance of the CNS and neurocognitive sequelae in asthma, highlighting potential opportunities for routine monitoring, therapeutic intervention, and recommend key areas for future research.

Association between non-cystic fibrosis bronchiectasis and the risk of incident dementia: A nationwide cohort study

BACKGROUND

Chronic lung diseases, such as chronic obstructive pulmonary disease or asthma, are associated with an increased risk of dementia. However, few data are available regarding the risk of dementia in individuals with bronchiectasis.

OBJECTIVES

To explore the association between bronchiectasis and the risk of incident dementia using a longitudinal population-based cohort.

METHODS

A total of 4,068,560 adults older than 50 years without previous dementia were enrolled from the Korean National Health Insurance Service database in 2009. They were followed up until the date of the diagnosis of dementia or December 31, 2020. The study exposure was the diagnosis of bronchiectasis, and the primary outcome was incident dementia comprising Alzheimer's disease and vascular dementia.

RESULTS

During the median follow-up duration of 9.3 years, the incidence of all-cause dementia was 1.6-fold higher in individuals with bronchiectasis than in those without bronchiectasis (15.0 vs. 9.3/1000 person-years, p < .001). In the multivariable Cox regression analysis, the risk of all dementia was significantly higher in individuals with bronchiectasis than in those without bronchiectasis (adjusted hazard ratio [aHR] 1.09, 95% confidence interval [CI] 1.04-1.14). In a subgroup analysis by dementia type, individuals with bronchiectasis had an increased risk of Alzheimer's disease compared to those without bronchiectasis (aHR 1.07, 95% CI 1.01-1.12); the risk of vascular dementia did not significantly differ between the two groups (aHR 1.05, 95% CI 0.90-1.21).

CONCLUSION

Bronchiectasis was associated with an increased risk of dementia, especially Alzheimer's disease.

Frailty and rehabilitation outcome in older patients with cardiorespiratory disease: preliminary multidimensional data

Chronic heart failure (CHF) and chronic obstructive pulmonary disease (COPD) are two clinical conditions often associated with cognitive dysfunctions, psychological distress, poor quality of life (QoL), and functional worsening. In addition, since patients suffering from these conditions are often older adults, frailty syndrome represents a further and important issue to be investigated. The present preliminary study aimed to perform a multidimensional assessment of CHF and/or COPD older patients (age ≥65) undergoing cardiac or pulmonary rehabilitation. The characteristics of the included patients (30 CHF and 30 COPD) resulted almost similar, except for the COPD patients' longer duration of illness and better performances in Addenbrooke's cognitive examination III subtests and short physical performance battery (SPPB). No significant differences were found in the frailty evaluation, but a consistent number of patients resulted to be frail (CHF=36.7% vs COPD=26.6%). After the rehabilitation program, a significant improvement was found in the whole sample concerning the executive functions (14.34±2.49 vs 15.62±2.22, p=0.001), quality of life (58.77±18.87 vs 65.82±18.45, p=0.003), depressive and anxious symptoms (6.27±4.21 vs 3.77±3.39, p=0.001 and 5.17±3.40 vs 3.38±3.21, p=0.001), frailty status [4.00 (3.00,5.00) vs 3.00 (3.00,5.00) p=0.035] and functional exercise abilities [SPPB, 7.40±3.10 vs 9.51±3.67, p=0.0002; timed up and go test, 14.62±4.90 vs 11.97±4.51, p<0.0001; 6-minute walking test, 353.85±127.62 vs 392.59±123.14, p=0.0002]. Preliminary results showed a substantial homogeneity of CHF and COPD older patients' cognitive, psychosocial, frailty, and functional characteristics. Nevertheless, the specific rehabilitation intervention appears promising in both clinical populations. This trial has been registered with the ClinicalTrials.gov, NCT05230927 registration number (clinicaltrials.gov/ct2/show/NCT05230927).

MASCoD-Multidimensional Assessment of Subjective Cognitive Decline

Subjective cognitive decline (SCD) is a subclinical cognitive impairment that is complained by the individual without being objectively supported at clinical, diagnostic, and neuropsychological levels. It can negatively impact on patient's frailty and quality of life, as well as on the caregiver's burden. Moreover, it can be prodromal to Mild Cognitive Impairment or dementia. Although the clinical manifestations of SCD can differ along with several cognitive domains, to date there are only screening tools to investigate subjective memory complaints. Thus, the first aim of this paper is to propose a preliminary English and Italian version of a new screening tool called MASCoD (Multidimensional Assessment of Subjective Cognitive Decline); the second aim is to propose its preliminary adoption on a pilot sample. This schedule is a brief test derived from the review of the literature and the clinical experience provided by an experts panelist. From pilot tests, it seems promising as it can help the professional to make differential diagnosis and to predict the risk of developing severe cognitive impairment over time, developing a personalized care path. This screening tool is brief, easily embeddable in usual clinical assessment, and administrable by different professionals. Furthermore, following validation, it will allow to collect manifold cognitive manifestations of SCD, addressing the shortage of previous validated instruments globally assessing cognition affected by this condition.

Risk of dementia or cognitive impairment in COPD patients: A meta-analysis of cohort studies

Purpose

A meta-analysis of cohort studies was performed to evaluate the association between COPD and the risk of dementia or cognitive impairment.

Methods

Cohort studies that evaluated the association between COPD and the risk of dementia or cognitive impairment were identified by a systematic search of PubMed, Embase, Web of Science, and Cochrane Library databases. The search time frame was from database establishment to April 12, 2022, with two reviewers independently screening the literature and extracting data. The Newcastle-Ottawa Quality Assessment Scale (NOS) was used to conduct the quality evaluation. Then, a meta-analysis was performed using Stata 15.1 software.

Results

Six cohort studies including 428,030 participants were included. The overall quality of the included studies was high, with an average NOS score of over 7. Meta-analysis showed that compared to those without COPD at baseline, patients with COPD were associated with a significant increased risk of dementia (RR = 1.24, 95% CI = 1.03 ~ 1.50, I2 = 96.6%, z = 2.25, p = 0.024) and cognitive impairment (RR = 1.30, 95% CI = 1.13 ~ 1.49, I2 = 50.1%, z = 3.72, p &lt; 0.001). Subgroup analysis suggested no significant difference in the risk of dementia among COPD patients of different genders. Nevertheless, in terms of age, the risk of dementia varied among COPD patients of different ages, which was most distinguished in patients younger than 65 years.

Conclusion

COPD patients have a higher risk of developing dementia or cognitive impairment compared to those without COPD, and this risk is not affected by gender but seems to be associated with age.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022325832.

Risk of developing cognitive impairment on patients with chronic obstructive pulmonary disease: A systematic review

BACKGROUND

The increasing number of chronic obstructive pulmonary disease (COPD) incidence has led to a great negative impact on older people's lives. This chronic disease was a critical and independent risk factor for cognitive function impairment in the elderly with mild cognitive impairment as a frequent feature. This systematic review aimed to examine the risk of developing cognitive impairment in COPD.

METHODS

A structured search of the literature was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement guideline, with a pre-determined search strategy starting from study identification, title and abstract screening, eligibility assessment, and inclusion of relevant study. The search was conducted in PubMed and MEDLINE via EBSCOhost, with restriction to human studies. The studies from inception until January 12, 2021.

RESULTS

Five original articles were included. Most studies found that patients with COPD had a higher chance of developing cognitive impairment, especially when patients were followed up for more than 5 years. We discovered that the risk of cognitive impairment seemed to be correlated with the length of time spent following the participants, with the highest risk of cognitive impairment being identified in those who had the longest observation period. It is critical to conduct cognitive screening from the time a diagnosis of COPD is obtained and on a continuing basis in order to recognize and treat these individuals appropriately.

CONCLUSION

There is a potential association between COPD and mild cognitive impairment. We encourage more studies to be done with higher sensitivity and specificity cognitive screening tools in the future to build better evidence and qualify to be analyzed quantitatively with meta-analysis.

A Comprehensive Systematic Review and Meta-Analysis of the Association between the Neutrophil-to-Lymphocyte Ratio and Adverse Outcomes in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

The neutrophil-to-lymphocyte ratio (NLR) predicts adverse outcomes in stable chronic obstructive pulmonary disease (COPD); however, its prognostic role in acute exacerbations (AECOPD) is less clear. We conducted a systematic review and meta-analysis of the association between the NLR on admission and adverse outcomes (mortality, need for mechanical ventilation, transfer to the intensive care unit, length of stay, pulmonary hypertension, or their combination) in AECOPD by searching PubMed, Web of Science, and Scopus from inception to April 2022. Risk of bias and certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist and the Grades of Recommendation, Assessment, Development, and Evaluation, respectively. In 15 studies (n = 10,038 patients), the NLR was significantly associated with the risk of adverse outcomes (odds ratio = 1.054, 95% CI 1.016 to 1.093, p = 0.005; low certainty of evidence; standard mean difference = 0.82, 95% CI 0.57 to 1.06, p < 0.001; high certainty of evidence). Pooled sensitivity, specificity, and area under the curve were 0.71 (95% CI 0.64 to 0.77), 0.73 (95% CI 0.65 to 0.80), and 0.78 (95% CI 0.74 to 0.81), respectively. In our study, the NLR on admission was significantly associated with adverse outcomes in AECOPD patients, suggesting the potential utility of this biomarker for early risk stratification and management in this group.

Association of geriatric syndromes in older adults with chronic obstructive pulmonary disease

Background

Geriatric syndromes (GS) are multi-factorial conditions that make older adults vulnerable to morbidities and poor outcomes. The main objective was to observe the frequency of GS in older patients with COPD.

Methods

A case-control study was conducted in the Geriatric department of a tertiary care hospital in India to evaluate geriatric syndromes including falls, cognitive impairment, frailty, functional impairment, urinary incontinence, malnutrition, and depression in patients with COPD and controls without COPD. The factors having a significant association with the occurrence of these GS in COPD patients were observed.

Results

In this study, 150 cases and 150 controls were included. The mean age of the participant was 65.85±5.54, with 76% males. Functional impairment, cognitive impairment, frailty, urinary incontinence, and malnutrition were significantly higher in COPD patients. The independent variables which increased the odds of geriatric syndromes were dyspnoea (≥2 mMRC grade) (AOR:3.54,95% CI:1.06-11.8) and low socioeconomic status (AOR: 4.14, 95% CI: 1.03-16.54), while male gender showed inverse association (AOR: 0.08,95% CI: 0.01-0.99).

Conclusion

Geriatric syndromes are common in older COPD patients, and assessment for them should be done routinely in these patients.

Association of chronic obstructive pulmonary disease with mild cognitive impairment and dementia risk: A systematic review and meta-analysis

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common public health issue that has been linked to cognitive dysfunction.

AIM

To investigate the relationship between COPD and a risk of mild cognitive impairment (MCI) and dementia.

METHODS

A comprehensive literature search of the PubMed, Embase, Google Scholar, and Cochrane Library electronic databases was conducted. Pooled odds ratios (OR) and mean differences (MD) with 95% confidence intervals (CIs) were calculated using a random or fixed effects model. Studies that met the inclusion criteria were assessed for quality using the Newcastle Ottawa Scale.

RESULTS

Twenty-seven studies met all the inclusion criteria. Meta-analysis yielded a strong association between COPD and increased risk of MCI incidence (OR = 2.11, 95%CI: 1.32-3.38). It also revealed a borderline trend for an increased dementia risk in COPD patients (OR = 1.16, 95%CI: 0.98-1.37). Pooled hazard ratios (HR) using adjusted confounders also showed a higher incidence of MCI (HR = 1.22, 95%CI: -1.18 to -1.27) and dementia (HR = 1.32, 95%CI: -1.22 to -1.43) in COPD patients. A significant lower mini-mental state examination score in COPD patients was noted (MD = -1.68, 95%CI: -2.66 to -0.71).

CONCLUSION

Our findings revealed an elevated risk for the occurrence of MCI and dementia in COPD patients. Proper clinical management and attention are required to prevent and control MCI and dementia incidence in COPD patients.

Respiratory Muscle Training Can Improve Cognition, Lung Function, and Diaphragmatic Thickness Fraction in Male and Non-Obese Patients with Chronic Obstructive Pulmonary Disease: A Prospective Study

Patients with chronic obstructive pulmonary disease (COPD) are frequently comorbid with mild cognitive impairment (MCI). Whether respiratory muscle training (RMT) is helpful for patients with COPD comorbid MCI remains unclear. Inspiratory muscle training (IMT) with or without expiratory muscle training (EMT) was performed. Patients were randomly assigned to the full training group (EMT + IMT) or the simple training group (IMT only). A total of 49 patients completed the eight-week course of RMT training. RMT significantly improved the maximal inspiratory pressure (MIP), the diaphragmatic thickness fraction and excursion, lung function, scores in the COPD assessment test (CAT), modified Medical Research Council (mMRC) scale scores, and MMSE. The between-group difference in the full training and single training group was not significant. Subgroup analysis classified by the forced expiratory volume in one second (FEV1) level of patients showed no significant differences in MIP, lung function, cognitive function, and walking distance. However, a significant increase in diaphragmatic thickness was found in patients with FEV1 ≥ 30%. We suggest that patients with COPD should start RMT earlier in their disease course to improve physical activity.

The Relationship Between Anxiety, Depression and Treatment Adherence in Chronic Obstructive Pulmonary Disease: A Systematic Review

Background

Almost half of the people with chronic obstructive pulmonary disease (COPD) do not adhere to the prescribed treatments and report anxiety and depression as comorbidities, resulting in higher rates of exacerbations, hospitalizations, and worse clinical outcomes.

Objective

This systematic review provided a synthesis of studies about the relationships between anxiety, depression, and adherence in people affected by COPD.

Methods

English language publications were searched in the PUBMED, SCOPUS, PsycInfo, Web of Science, PsycArticles, and Cochrane Library databases from December 2020 to March 2021, following PRISMA guidelines. The reference lists of eligible studies and other relevant systematic reviews were also searched. Data extraction and critical appraisal were undertaken by two reviewers working independently. The reference lists of eligible studies and other relevant systematic reviews were also searched. Data extraction and critical appraisal were undertaken by two reviewers working independently.

Results

A total of 34 studies (23 quantitative and 2 qualitative studies, 9 reviews) were included. The relationship between depression and treatment adherence was significant and negative. Adherence to both rehabilitation, psychological, and antidepressant pharmacological treatments in depressed patients was linked to a decreased risk of hospitalization. Moreover, depressed patients compliant with an antidepressant were more likely to adherent to COPD maintenance inhalers. On the other hand, the associations between anxiety and adherence were poorly investigated and high heterogeneity characterized the studies, leading to a weak and variable relationship as well as too few interventions.

Conclusion

The systematic review highlights the variability in estimates of the relationship between depression, anxiety, and treatment adherence in COPD. It could be explained by methodological differences across the included studies. This suggests that standardization is critical to improving the precision of the estimates. Recommendations for future research include attention to causal inferences, an exploration of mechanisms to explain the relationships between both anxiety and depression and adherence in COPD, and a comprehensive, systematic approach.