Risk of incident dementia and cognitive impairment in patients with chronic obstructive pulmonary disease (COPD): A large UK population-based study

Association of peripheral B cells and delirium: combined single-cell sequencing and Mendelian randomization analysis

Background

Delirium seriously affects the prognosis of patients and greatly reduces the ability to work and live. Peripheral inflammatory events may contribute to the development of delirium, the mechanism of which is still unclear. There is a lack of effective diagnostic and treatments for delirium in clinical practice. The study aims to investigate alterations in peripheral immune cell subsets under inflammatory stress and to explore causal associations with delirium.

Methods

Single-cell transcriptional sequencing data of human peripheral blood mononuclear cells (PBMC) before and after lipopolysaccharide (LPS) intervention were processed by the Seurat package in R software. PBMC subsets and cellular markers were defined after downscaling and clustering by the Harmony algorithm to identify characteristic subsets in the context of inflammatory stress. Subsequently, a two-sample Mendelian randomization (MR) study was used to explore the causal associations of these inflammation-related PBMC subsets and their molecular phenotypes with delirium. Based on publicly available genetic data, the study incorporated 70 PBMC-associated immune traits, including 8 types of circulating immune cells, 33 B cell subsets and molecular phenotypes, 13 T cell subsets, and 16 B cell-associated cytokines. The results were also validated for robustness, heterogeneity, and horizontal pleiotropy.

Results

Under LPS-induced inflammatory stress, B cells, T cells, monocytes, and dendritic cells in human PBMC showed significant activation and quantitative changes. Of these, only lymphocyte and B cell counts were causally associated with delirium risk. This risk link is also seen in the TNF pathway. Further studies of B cells and their subsets revealed that this association may be related to unswitched memory B cells and CD27 expressed on memory B cells. Annotation of the screened SNPs revealed significant polymorphisms in CD27 and CD40 annotated by rs25680 and rs9883798, respectively. The functions of the key annotated genes may be related to the regulation of immune responses, cell differentiation, proliferation, and intercellular interactions.

Conclusion

The present study revealed the potential possibility that B cell, memory B cell subset, and TNF-related molecules may be involved in the development of delirium due to peripheral inflammation, which can provide clues for further investigation of delirium prevention and treatment strategies.

Risks of dementia in a general Japanese older population with preserved ratio impaired spirometry: The Hisayama Study

BACKGROUND

Studies on the association between preserved ratio impaired spirometry (PRISm) and dementia are limited. Indeed, PRISm has often been overlooked or ignored as an index of lung function impairment. Therefore, we investigated the association of PRISm with the risk for the development of dementia in an older Japanese population.

METHODS

A total of 1202 community-dwelling, older Japanese participants aged ≥65 years without dementia were followed up for a median of 5.0 years. Participants were categorized by spirometry as follows: normal spirometry (FEV1/FVC ≥0.70 and FEV1 ≥80% predicted), PRISm (≥0.70 and <80%), airflow limitation (AFL) Global Initiative for Chronic Obstructive Lung Disease (GOLD) 1 (<0.70 and ≥80%), and AFL GOLD 2 to 4 (<0.70 and <80%). Hazard ratios (HRs) and their 95% confidence intervals (CIs) were computed using a Cox proportional hazards model.

RESULTS

During the follow-up period, 122 participants developed dementia. The age- and sex-adjusted incidences of dementia in the participants with normal spirometry, PRISm, AFL GOLD 1, and AFL GOLD 2 to 4 were 20.5, 37.0, 18.4, and 28.6 per 1000 person-years, respectively. Participants with PRISm had a higher risk of dementia (HR 2.04 [95%CI, 1.19-3.49]) than those with normal spirometry after adjusting for confounders. Moreover, both reduced FEV1% predicted values and FVC% predicted values were associated with the risk for dementia.

CONCLUSION

PRISm was associated with an increased risk of dementia in a general older Japanese population.

Roles of Omega-3 Polyunsaturated Fatty Acids in Managing Cognitive Impairment in Chronic Obstructive Pulmonary Disease: A Review

Chronic obstructive pulmonary disease (COPD) contributes significantly to the death of people worldwide, especially the elderly. An essential feature of COPD is pulmonary inflammation, which results from long-term exposure to noxious substances from cigarette smoking and other environmental pollutants. Pulmonary inflammatory mediators spill over to the blood, leading to systemic inflammation, which is believed to play a significant role in the onset of a host of comorbidities associated with COPD. A substantial comorbidity of concern in COPD patients that is often overlooked in COPD management is cognitive impairment. The exact pathophysiology of cognitive impairment in COPD patients remains a mystery; however, hypoxia, oxidative stress, systemic inflammation, and cerebral manifestations of these conditions are believed to play crucial roles. Furthermore, the use of medications to treat cognitive impairment symptomatology in COPD patients has been reported to be associated with life-threatening adverse effects, hence the need for alternative medications with reduced side effects. In this Review, we aim to discuss the impact of cognitive impairment in COPD management and the potential mechanisms associated with increased risk of cognitive impairment in COPD patients. The promising roles of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) in improving cognitive deficits in COPD patients are also discussed. Interestingly, ω-3 PUFAs can potentially enhance the cognitive impairment symptomatology associated with COPD because they can modulate inflammatory processes, activate the antioxidant defence system, and promote amyloid-beta clearance from the brain. Thus, clinical studies are crucial to assess the efficacy of ω-3 PUFAs in managing cognitive impairment in COPD patients.

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.

Comorbid Cognitive Impairment in Chronic Obstructive Pulmonary Disease (COPD): Current Understanding, Risk Factors, Implications for Clinical Practice, and Suggested Interventions

Cognitive impairment is a common comorbidity in patients with COPD, significantly impacting health and clinical outcomes. Yet it remains under investigated and is largely overlooked. Although the exact cause of cognitive impairment in patients with COPD is still unclear, factors such as hypoxemia, vascular disease, smoking, exacerbation, and physical inactivity have been suggested. While international guidelines recommend identifying comorbidity in patients with COPD, such as cognitive impairment, cognitive assessment is not yet part of the routine assessment. Unidentified cognitive deficits in patients with COPD may have severe impacts on clinical management, resulting in an inability to maintain functional independence, poor self-management, and a greater dropout from pulmonary rehabilitation programs. There is a need to consider cognitive screening as a part of COPD assessment to promote early detection of cognitive impairment. Recognizing cognitive impairment early in the course of the illness allows the development of individualized interventions to meet patients' needs and improve clinical outcomes. Pulmonary rehabilitation should be tailored to cognitively impaired patients with COPD to maximize the benefits and minimize the incompletion rate.

Comorbidity among inpatients with dementia: a preliminary cross-sectional study in West China

OBJECTIVE

To investigate comorbidities among hospitalized patients with dementia.

METHOD

Data were extracted from the discharge records in our hospital. Comorbidities based on ICD-10 were selected from the Charlson Comorbidity Index (CCI) and Elixhauser Comorbidity Index (ECI). The distributions of these comorbidities were described in dementia inpatients and age- and sex-matched nondementia controls, as well as in inpatients with Alzheimer's disease and vascular dementia. A logistic regression model was applied to identify dementia-specific morbid conditions.

RESULTS

A total of 3355 patients with dementia were included, with a majority of 1503 (44.8%) having Alzheimer's disease, 395 (11.8%) with vascular dementia, and 441 (13.1%) with mixed dementia. The mean number of comorbidities was 3.8 in dementia patients (vs. 2.9 in controls). The most prevalent comorbidities in inpatients with dementia compared with those without dementia were cerebral vascular disease (73.0% vs. 35.9%), hypertension (62.8% vs. 56.2%), and peripheral vascular disease (53.7% vs. 31.2%). Comorbidities associated with dementia included epilepsy (OR 4.8, 95% CI 3.5-6.8), cerebral vascular disease (OR 4.1, 95% CI 3.7-4.5), depression (OR 4.0, 95% CI 3.2-5.0), uncomplicated diabetes (OR 1.5, 95% CI 1.4-1.7), peripheral vascular disease (OR 1.8, 95% CI 1.6-2.0), rheumatoid arthritis collagen vascular disease (OR 1.7, 95% CI 1.3-2.3), and anemia (OR 1.2, 95% CI 1.04-1.3). Some comorbidities suggested a protective effect against dementia. They were hypertension (OR 0.8, 95% CI 0.7-0.9), COPD (OR 0.6, 95% CI 0.5-0.6), and solid tumor without metastasis (OR 0.4, 95% CI 0.3-0.4). Vascular dementia has more cardiovascular and cerebrovascular comorbidities than Alzheimer's disease.

CONCLUSION

Patients with dementia coexisted with more comorbidities than those without dementia. Comorbidities (esp. cardio-cerebral vascular risks) in patients with vascular dementia were more than those in patients with AD. Specifically, vascular and circulatory diseases, epilepsy, diabetes and depression increased the risk of dementia.

Associations of Lung Function Decline with Risks of Cognitive Impairment and Dementia: A Meta-Analysis and Systematic Review

BACKGROUND

There are controversies surrounding the effects of lung function decline on cognitive impairment and dementia.

OBJECTIVE

We conducted a meta-analysis and systematic review to explore the associations of lung function decline with the risks of cognitive impairment and dementia.

METHODS

The PubMed, EMBASE, and the Cochrane Library were searched to identify prospective studies published from database inception through January 10, 2023. We pooled relative risk (RR) and 95% confidence intervals (CI) using random-effects models. The Egger test, funnel plots, meta-regression, sensitivity, and subgroup analyses were conducted to detect publication bias and investigate the source of heterogeneity.

RESULTS

Thirty-three articles with a total of 8,816,992 participants were subjected to meta-analysis. Poorer pulmonary function was associated with an increased risk of dementia (FEV: RR = 1.25 [95% CI, 1.17-1.33]; FVC: RR = 1.40 [95% CI, 1.16-1.69]; PEF: RR = 1.84 [95% CI, 1.37-2.46]). The results of the subgroup analyses were similar to the primary results. Individuals with lung diseases had a higher combined risk of dementia and cognitive impairment (RR = 1.39 [95% CI, 1.20-1.61]). Lung disease conferred an elevated risk of cognitive impairment (RR = 1.37 [95% CI, 1.14-1.65]). The relationship between lung disease and an increased risk of dementia was only shown in total study participants (RR = 1.32 [95% CI, 1.11-1.57]), but not in the participants with Alzheimer's disease (RR = 1.39 [95% CI, 1.00-1.93]) or vascular dementia (RR = 2.11 [95% CI, 0.57-7.83]).

CONCLUSION

Lung function decline was significantly associated with higher risks of cognitive impairment and dementia. These findings might provide implications for the prevention of cognitive disorders and the promotion of brain health.

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.

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.

Cognitive impairment caused by hypoxia: from clinical evidences to molecular mechanisms

Hypoxia is a state of reduced oxygen supply and excessive oxygen consumption. According to the duration of hypoxic period, it can be classified as acute and chronic hypoxia. Both acute and chronic hypoxia could induce abundant neurological deficits. Although there have been significant advances in the pathophysiological injuries, few studies have focused on the cognitive dysfunction. In this review, we focused on the clinical evidences and molecular mechanisms of cognitive impairment under acute and chronic hypoxia. Hypoxia can impair several cognitive domains such as attention, learning and memory, procession speed and executive function, which are similar in acute and chronic hypoxia. The severity of cognitive deficit correlates with the duration and degree of hypoxia. Recovery can be achieved after acute hypoxia, while sequelae or even dementia can be observed after chronic hypoxia, perhaps due to the different molecular mechanisms. Cardiopulmonary compensatory response, glycolysis, oxidative stress, calcium overload, adenosine, mitochondrial disruption, inflammation and excitotoxicity contribute to the molecular mechanisms of cognitive deficit after acute hypoxia. During the chronic stage of hypoxia, different adaptive responses, impaired neurovascular coupling, apoptosis, transcription factors-mediated inflammation, as well as Aβ accumulation and tau phosphorylation account for the neurocognitive deficit. Moreover, brain structural changes with hippocampus and cortex atrophy, ventricle enlargement, senile plaque and neurofibrillary tangle deposition can be observed under chronic hypoxia rather than acute hypoxia.

Comorbidity patterns in institutionalized older adults affected by dementia

Introduction

Dementia is common in nursing homes (NH) residents. Defining dementia comorbidities is instrumental to identify groups of persons with dementia that differ in terms of health trajectories and resources consumption. We performed a cross‐sectional study to identify comorbidity patterns and their associated clinical, behavioral, and functional phenotypes in institutionalized older adults with dementia.

Methods

We analyzed data on 2563 Italian NH residents with dementia, collected between January 2014 and December 2018 using the multidimensional assessment instrument interRAI Long‐Term Care Facility (LTCF). A standard principal component procedure was used to identify comorbidity patterns. Linear regression analyses were used to ascertain correlates of expression of the different patterns.

Results

Among NH residents with dementia, we identified three different comorbidity patterns: (1) heart diseases, (2) cardiovascular and respiratory diseases and sensory impairments, and (3) psychiatric diseases. Older age significantly related to increased expression of the first two patterns, while younger patients displayed increased expression of the third one. Recent hospital admissions were associated with increased expression of the heart diseases pattern (β = 0.028; 95% confidence interval [CI] 0.003 to 0.05). Depressive symptoms and delirium episodes increased the expression of the psychiatric diseases pattern (β = 0.130, 95% CI 0.10 to 0.17, and β 0.130, CI 0.10 to 0.17, respectively), while showed a lower expression of the heart diseases pattern.

Discussion

We identified different comorbidity patterns within NH residents with dementia that differ in term of clinical and functional profiles. The prompt recognition of health needs associated to a comorbidity pattern may help improve long‐term prognosis and quality of life of these individuals.

Highlights

Defining dementia comorbidities patterns in institutionalized older adults is key.

Institutionalized older adults with dementia express different care needs.

Comorbidity patterns are instrumental to identify different patients’ phenotypes.

Phenotypes vary in terms of health trajectories and demand different care plans.

Prompt recognition of phenotypes in nursing homes can positively impact on outcomes.