COPD and cognitive impairment: the role of hypoxemia and oxygen therapy

Effect of 12-week head-down strong abdominal breathing on cognitive function in patients with stable chronic obstructive pulmonary disease: a single-centre randomised controlled trial protocol

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) often suffer from a combination of mild cognitive impairment (MCI) and a significant reduction in their quality of life. In the exercise programme of pulmonary rehabilitation (PR), pulmonary rehabilitation intervention is often carried out by enhancing respiratory function. Strong abdominal breathing is a kind of breathing method, through which the diaphragm can be exercised, thereby enhancing the deflection distance of the diaphragm during breathing and improving respiratory function. The inversion trainer can meet the different angles of head-down training and also has the characteristics of low cost, easy to operate, and use a wide range of scenarios. According to currently available data, strong abdominal breathing in combination with head-down position has not yet been used in pulmonary rehabilitation in this type of rehabilitation programme. It is valuable to use this device to study PR of cognitive function in patients with COPD.

METHODS

This study was a 12-week single-centre randomised controlled trial and blinding the assessors and data processors of the test. Recruitment is planned for January 1, 2024. It is expected that 81 patients with stable COPD combined with MCI will be recruited and randomly assigned to the head-down strong abdominal breathing group (HG), the fitness qigong eight-duanjin group (BDJ), and the control group (CG) in a 1:1:1 ratio. Using fNIRS (functional near-infrared spectroscopy) to assess brain oxygen availability before and after pulmonary rehabilitation in three periods: before, during and after the intervention. Cognitive functioning is also assessed using the Overall Cognitive Assessment Scale, the Specific Cognitive Functioning Assessment Scale and the Cognitive Behavioural Ability Test.

TRIAL REGISTRATION

The Specialised Committee on Scientific Research and Academic Ethics of the Academic Committee of Anqing Normal University approved the project (ANU2023001). China Clinical Trial Registry approved the study (ChiCTR2300075400) with a registration date of 2023/09/04.

DISCUSSION

The aim of this study was to explore novel exercise rehabilitation methods to improve cognitive function in COPD patients. It results in a lower financial burden and higher participation in pulmonary rehabilitation and improves the quality of survival of patients with COPD.

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.

The interplay of physical and cognitive function in rehabilitation of interstitial lung disease patients: a narrative review

Background and Objective

Interstitial lung disease (ILD) encompasses several diverse pulmonary pathologies that result in abnormal diffuse parenchymal changes. When prescribing rehabilitation, several additional factors need to be considered as a result of aging, polypharmacy, and comorbidities manifested in ILD patients. This review aims to discuss issues related to frailty, skeletal muscle and cognitive function that limit physical activities in ILD patients. It will also highlight exercise training and propose complementary strategies for pulmonary rehabilitation.

Methods

A literature search was performed in MEDLINE, CINAHL (inception to October 19th, 2022) using search terms based on concepts of: idiopathic pulmonary fibrosis or interstitial lung disease; frailty; muscular atrophy; skeletal muscle dysfunction; cognitive dysfunction; sleep quality; sleep disorders; anxiety disorders; or depressive disorders. After eligible texts were screened, additional references were included from references cited in the screened articles.

Key Content and Findings

Frailty and skeletal muscle dysfunction are common in ILD. Weight loss, exhaustion, and anti-fibrotic medications can impact frailty, whereas physical inactivity, aging, corticosteroids and hypoxemia can contribute to sarcopenia (loss of muscle mass and function). Frailty is associated with worse clinical status, exercise intolerance, skeletal muscle dysfunction, and decreased quality of life in ILD. Sarcopenia appears to influence wellbeing and can potentially affect overall physical conditioning, cognitive function and the progression of ILD. Optimal assessment tools and effective strategies to prevent and counter frailty and sarcopenia need to be determined in ILD patients. Even though cognitive impairment is evident in ILD, its prevalence and underlying neurobiological model of contributing factors (i.e., inflammation, disease severity, cardiopulmonary status) requires further investigation. How ILD affects cognitive interference, motor control and consequently physical daily activities is not well defined. Strategies such as pulmonary rehabilitation, which primarily focuses on strength and aerobic conditioning have demonstrated improvements in ILD patient outcomes. Future incorporation of interval training and the integration of motor learning could improve transfer of rehabilitation strategies to daily activities.

Conclusions

Numerous underlying etiologies of ILD contribute to frailty, skeletal muscle and cognitive function, but their respective neurobiologic mechanisms require further investigation. Exercise training increases physical measures, but complementary approaches may improve their applicability to improve daily activities.

Cognitive Interventions in Individuals With Chronic Respiratory Diseases: Protocol for a Systematic Review

BACKGROUND

Chronic respiratory diseases (CRDs) may cause reduced oxygen availability to organs and body tissues, leading to an increased risk for ischemic damage, which can result in brain tissue injury. This damage can lead to a myriad of neurological symptoms contributing to cognitive decline. Cognitive interventions may attenuate cognitive deficits in people with CRDs; however, the effects have not yet been systematically summarized in the literature.

OBJECTIVE

The purpose of this systematic review is to assess the effects of cognitive interventions (including cognitive behavioral therapy and transcranial brain stimulation) on cognitive function (primary outcome), HRQL, self-management, symptoms, physical activity, physical function, ability to complete activities of daily living (ADLs), hospital admissions, functional capacity, functional performance, psychological and social outcomes, exacerbations, healthcare utilization, and survival in individuals with CRDs.

METHODS

This review will be conducted in accordance with the Cochrane handbook for systematic reviews of interventions and reported following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Searches will be performed in MEDLINE, Embase, Emcare, PsycINFO, Scopus, and CINAHL. Articles will be included if they focus on the effects of cognitive interventions on adults with CRDs, are published in peer-reviewed journals, and are written in English, French, or Portuguese. Risk of bias will be evaluated with the Cochrane Risk of Bias 2 tool for randomized controlled trials, and the Risk of Bias in Non-randomized Studies of Interventions tool for nonrandomized studies. Meta-analyses will be performed if at least 2 studies provided sufficient data for a specific outcome. The GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) assessment will be used to evaluate the overall quality of the evidence.

RESULTS

This systematic review was initiated in November 2022 and registered with PROSPERO in February 2023, prior to title and abstract screening. Full-text screening of articles will be completed in June 2023. Data extraction and drafting of the manuscript will occur from July 2023 to August 2023, with expected publication in February 2024.

CONCLUSIONS

This systematic review will summarize the effects of cognitive interventions on cognitive function in people with CRDs. It will guide health care professionals in selecting evidence-based strategies to enhance cognitive well-being and overall health outcomes for individuals with CRDs. Additionally, it will identify research gaps and highlight areas for future exploration, supporting researchers in advancing knowledge in this field.

TRIAL REGISTRATION

PROSPERO CRD42023396234; https://tinyurl.com/mwjrfbxv.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/48235.

Feasibility of a Home-Based Cognitive-Physical Exercise Program in Patients With Chronic Obstructive Pulmonary Disease: Protocol for a Feasibility and Pilot Randomized Controlled Trial

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a progressive condition associated with physical and cognitive impairments contributing to difficulty in performing activities of daily living (ADLs) that require dual tasking (eg, walking and talking). Despite evidence showing that cognitive decline occurs among patients with COPD and may contribute to functional limitations and decreased health-related quality of life (HRQL), pulmonary rehabilitation continues to focus mainly on physical training (ie, aerobic and strength exercises). An integrated cognitive and physical training program compared to physical training alone may be more effective in increasing dual-tasking ability among people living with COPD, leading to greater improvements in performance of ADLs and HRQL.

OBJECTIVE

The aims of this study are to evaluate the feasibility of an 8-week randomized controlled trial of home-based, cognitive-physical training versus physical training for patients with moderate to severe COPD and derive preliminary estimates of cognitive-physical training intervention efficacy on measures of physical and cognitive function, dual task performance, ADLs, and HRQL.

METHODS

A total of 24 participants with moderate to severe COPD will be recruited and randomized into cognitive-physical training or physical training. All participants will be prescribed an individualized home physical exercise program comprising 5 days of moderate-intensity aerobic exercise (30-50 minutes/session) and 2 days of whole-body strength training per week. The cognitive-physical training group will also perform cognitive training for approximately 60 minutes, 5 days per week via the BrainHQ platform (Posit Science Corporation). Participants will meet once weekly with an exercise professional (via videoconference) who will provide support by reviewing the progression of their training and addressing any queries. Feasibility will be assessed through the recruitment rate, program adherence, satisfaction, attrition, and safety. The intervention efficacy regarding dual task performance, physical function, ADLs, and HRQL will be evaluated at baseline and at 4 and 8 weeks. Descriptive statistics will be used to summarize intervention feasibility. Paired 2-tailed t tests and 2-tailed t tests will be used to compare the changes in the outcome measures over the 8-week study period within and between the 2 randomized groups, respectively.

RESULTS

Enrollment started in January 2022. It is estimated that the enrollment period will be 24 months long, with data collection to be completed by December 2023.

CONCLUSIONS

A supervised home-based cognitive-physical training program may be an accessible intervention to improve dual-tasking ability in people living with COPD. Evaluating the feasibility and effect estimates is a critical first step to inform future clinical trials evaluating this approach and its effects on physical and cognitive function, ADL performance, and HRQL.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05140226; https://clinicaltrials.gov/ct2/show/NCT05140226.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/48666.

In-Hospital and One-Year Outcomes of Transcatheter Aortic Valve Replacement in Patients Requiring Supplemental Home Oxygen Use

Background

There have been limited reports with inconsistent results on the impact of long-term use of oxygen therapry (LTOT) in patients treated with transcatheter aortic valve replacement (TAVR).

Methods

We compared in-hospital and intermediate TAVR outcomes in 150 patients requiring LTOT (home O₂ cohort) with 2,313 non-home O₂ patients.

Results

Home O₂ patients were younger, and had more comorbidities including chronic obstructive pulmonary disease (COPD), diabetes, carotid artery disease, lower forced expiratory volume (FEV₁) (50.3±21.1% vs. 75.0±24.7%, P < 0.001), and lower diffusion capacity (DLCO, 48.6±19.2% vs. 74.6±22.4%, P < 0.001). These differences represented higher baseline Society of Thoracic Surgeons (STS) risk score (15.5±10.2% vs. 9.3±7.0%, P < 0.001) and lower pre-procedure Kansas City Cardiomyopathy Questionnaire (KCCQ-12) scores (32.5 ± 22.2 vs. 49.1 ± 25.4, P < 0.001). The home O₂ cohort required higher use of alternative TAVR vascular access (24.0% vs. 12.8%, P = 0.002) and general anesthesia (51.3% vs. 36.0%, P < 0.001). Compared to non-home O₂ patients, home O₂ patients showed increased in-hospital mortality (5.3% vs. 1.6%, P = 0.001), procedural cardiac arrest (4.7% vs. 1.0%, P < 0.001), and postoperative atrial fibrillation (4.0% vs. 1.5%, P = 0.013). At 1-year follow-up, the home O₂ cohort had a higher all-cause mortality (17.3% vs. 7.5%, P < 0.001) and lower KCCQ-12 scores (69.5 ± 23.8 vs. 82.1 ± 19.4, P < 0.001). Kaplan-Meir analysis revealed a lower survival rate in the home O₂ cohort with an overall mean (95% confidence interval (CI)) survival time of 6.2 (5.9 - 6.5) years (P < 0.001).

Conclusion

Home O₂ patients represent a high-risk TAVR cohort with increased in-hospital morbidity and mortality, less improvement in 1-year KCCQ-12, and increased mortality at intermediate follow-up.

The role of structured exercise interventions on cognitive function in older individuals with stable Chronic Obstructive Pulmonary Disease: A scoping review

A decline in cognitive performance has been associated with disease severity, exacerbations rate, presence of comorbidities, and low activity level in people with chronic obstructive pulmonary disease (COPD). Participation in exercise programs appears to have neuroprotective effects and to improve cognitive performance in older people. The present work undertook a scoping review of the effects of exercise-based interventions on cognitive function in older individuals with stable COPD.

METHODS

The methodological framework for scoping review was used and electronic searches of five databases performed. Original research and observational studies published between January 2010 and December 2021, administering exercise-based interventions and cognitive function evaluation, were included.

RESULTS

Of 13 full-text manuscripts assessed for eligibility, five were allocated to analysis. Three studies administered exercise training within pulmonary outpatient rehabilitation program (PR), and one inpatient PR. The fifth study conducted a structured training intervention in which either aerobic or a combination with resistance exercises were included. Twelve cognitive function screening tools were used in the five studies included in the analysis. Results extracted were based on 245 COPD (33% female) with moderate to very-severe airflow limitation. Interventions ranged from 12 to 36 sessions. Studies reported statistically significant improvements after intervention in different cognitive function domains, such as global cognition, immediate and delayed recall ability, cognitive flexibility, verbal fluency, attention, abstract reasoning, praxis ability.

CONCLUSIONS

Exercise-based interventions improve several areas of cognitive function in patients with stable COPD. However, the magnitude of gain varies among studies, and this is possibly due to the heterogeneity of tests used. Future research is needed to validate the optimal battery of screening tests, and to support the definition of guidelines for cognitive function evaluation in COPD.

Increased exploration and hyperlocomotion in a cigarette smoke and LPS-induced murine model of COPD: linking pulmonary and systemic inflammation with the brain

Brain-related comorbidities are frequently observed in chronic obstructive pulmonary disease (COPD) and are related to increased disease progression and mortality. To date, it is unclear which mechanisms are involved in the development of brain-related problems in COPD. In this study, a cigarette smoke and lipopolysaccharide (LPS) exposure murine model was used to induce COPD-like features and assess the impact on brain and behavior. Mice were daily exposed to cigarette smoke for 72 days, except for days 42, 52, and 62, on which mice were intratracheally exposed to the bacterial trigger LPS. Emphysema and pulmonary inflammation as well as behavior and brain pathology were assessed. Cigarette smoke-exposed mice showed increased alveolar enlargement and numbers of macrophages and neutrophils in bronchoalveolar lavage. Cigarette smoke exposure resulted in lower body weight, which was accompanied by lower serum leptin levels, more time spent in the inner zone of the open field, and decreased claudin-5 and occludin protein expression levels in brain microvessels. Combined cigarette smoke and LPS exposure resulted in increased locomotion and elevated microglial activation in the hippocampus of the brain. These novel findings show that systemic inflammation observed after combined cigarette smoke and LPS exposure in this COPD model is associated with increased exploratory behavior. Findings suggest that neuroinflammation is present in the brain area involved in cognitive functioning and that blood-brain barrier integrity is compromised. These findings can contribute to our knowledge about possible processes involved in brain-related comorbidities in COPD, which is valuable for optimizing and developing therapy strategies.

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.

Lung function impairment in relation to cognition and vascular brain lesions: the Rotterdam Study

OBJECTIVE

To investigate the association of chronic obstructive pulmonary disease (COPD) and Preserved Ratio Impaired Spirometry (PRISm) with cognitive performance and presence of vascular brain lesions (VBL).

METHODS

We determined both cross-sectional and longitudinal association of lung function impairment with cognition, as well as cross-sectional association of lung function impairment with VBL, in the general population. Between 2009 and 2014 we included 3,941 participants from the Rotterdam Study with spirometry tests, brain MRI scans and cognition tests, of whom 1815 had follow-up data on cognition.

RESULTS

Our finding indicated that cross-sectionally, participants with PRISm or COPD GOLD2-4 had a worse global cognitive performance. We did not find differences in cognition over time between those with normal spirometry versus those with lung function impairment. In addition, PRISm and COPD GOLD2-4 were associated with a higher prevalence of lacunar infarcts compared to normal spirometry.

CONCLUSIONS

This study suggests that persons with COPD GOLD2-4 or restrictive lung function, defined as PRISm, are characterized by poorer global cognitive function and a higher prevalence of lacunar infarcts.

Recommendations for traveling to altitude with neurological disorders

BACKGROUND

Several neurological conditions might worsen with the exposure to high altitude (HA). The aim of this review was to summarize the available knowledge on the neurological HA illnesses and the risk for people with neurological disorders to attend HA locations.

METHODS

A search of literature was conducted for several neurological disorders in PubMed and other databases since 1970. The neurological conditions searched were migraine, different cerebrovascular disease, intracranial space occupying mass, multiple sclerosis, peripheral neuropathies, neuromuscular disorders, epileptic seizures, delirium, dementia, and Parkinson's disease (PD).

RESULTS

Attempts were made to classify the risk posed by each condition and to provide recommendations regarding medical evaluation and advice for or against traveling to altitude. Individual cases should be advised after careful examination and risk evaluation performed either in an outpatient mountain medicine service or by a physician with knowledge of HA risks. Preliminary diagnostic methods and anticipation of neurological complications are needed.

CONCLUSIONS

Our recommendations suggest absolute contraindications to HA exposure for the following neurological conditions: (1) Unstable conditions-such as recent strokes, (2) Diabetic neuropathy, (3) Transient ischemic attack in the last month, (4) Brain tumors, and 5. Neuromuscular disorders with a decrease of forced vital capacity >60%. We consider the following relative contraindications where decision has to be made case by case: (1) Epilepsy based on recurrence of seizure and stabilization with the therapy, (2) PD (± obstructive sleep apnea syndrome-OSAS), (3) Mild Cognitive Impairment (± OSAS), and (4) Patent foramen ovale and migraine have to be considered risk factors for acute mountain sickness.

Impairment of Cognitive Function in Different Domains Early After Lung Transplantation

In this prospective observational pilot study patients with the diagnosis of end-stage lung disease and listed for lung transplantation underwent a cognitive function test battery before and after lung transplantation to investigate postoperative cognitive function in three domains (visual and verbal memory, executive functioning, concentration/speed of processing). Additionally we investigated intraoperative risk factors for postoperative cognitive dysfunction. In total, 24 patients were included in this pilot study. The incidence of postoperative cognitive dysfunction was 58.3%. In the cognitive dysfunction group, the domains executive functioning and concentration/attention were significantly impaired whereas memory was not affected. Patients with cognitive impairment had a significantly longer ICU stay. The strongest independent risk factor for the development of cognitive dysfunction was operation time. No influence of cerebral oxygen desaturations on cognitive dysfunction was found. This might have important implications for early psychological rehabilitation strategies in this high-risk patient collective.

Effect of 12-week pulmonary rehabilitation on cognitive function in patients with stable chronic obstructive pulmonary disease: study protocol for a single-center randomised controlled trial

INTRODUCTION

Cognitive impairment, an important complication in patients with chronic obstructive pulmonary disease (COPD), seriously affects self-management of the disease and quality of life (QoL). As an exercise-based intervention programme, pulmonary rehabilitation (PR)-especially aerobic exercise (mainly mind-body exercise) and resistance exercise (RE)-has been proposed for its potential effectiveness in improving cognitive function. However, there is still a lack of strong evidence for PR's effectiveness. In this study, we expect to clarify the effects of pulmonary-based Qigong exercise and elastic band-based RE on cognitive function in patients with COPD and to fill in the relevant evidence blanks.

METHODS AND ANALYSIS

This study is a single-centre randomised controlled trial with assessor and data analyst blinding. We will recruit 108 participants with stable COPD starting on 23 December 2019, and randomly allocate them into the pulmonary-based Qigong exercise group, elastic band-based RE group, pulmonary-based Qigong exercise and elastic band-based RE combined group, or control group at a 1:1:1:1 ratio. Participants in intervention groups will perform 30 min of exercise two times per day, 5 days a week, for 12 weeks. The primary outcome will be the global cognitive function as assessed by the Montreal Cognitive Assessment and auditory event-related potential P300. Secondary outcomes will include the specific cognitive domains-attention, memory, executive function, verbal fluency and mental-processing speed; psychological functions and QoL. Exploratory outcomes will include grey matter volume and levels of inflammatory mediators. Outcomes will be measured before and after the interventions.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the Ethics Committee of Yue-Yang Integrative Medicine Hospital, an affiliate of Shanghai University of Traditional Chinese Medicine, Shanghai, China (Grant No. 2019-141). Written informed consent will be obtained from each participant before any procedures are performed. The findings will be published in peer-reviewed journals and presented at academic conferences.

TRIAL REGISTRATION NUMBER

ChiCTR1900026869; pre-results.

Moderate-to-Severe Obstructive Sleep Apnea and Cognitive Function Impairment in Patients with COPD

Purpose

Prior studies have indicated that patients with chronic obstructive pulmonary disease (COPD) exhibit significant cognitive defects on neuropsychological testing. Obstructive sleep apnea (OSA) is common in patients with COPD and is associated with reduced cognitive function; however, the combined impact of these two conditions on cognitive function is unknown. The aim of the study was to investigate the impact of OSA on cognitive impairment in patients with COPD.

Methods

Sixty-five stable COPD patients aged over 60 years underwent overnight polysomnography (PSG). Global cognitive functions were evaluated using the Mini-Mental State Examination (MMSE).

Results

Compared to patients with COPD alone, patients with both COPD and OSA performed worse on the MMSE (25.5±2.9 vs 23.5±3.2; p=0.01) and were more likely to be at risk for developing dementia based on the MMSE score (MMSE≤24) (31% vs 66%; p<0.01), independent of key demographic, educational and medical variables known to affect cognitive function in COPD. COPD patients with an apnea hypopnea index (AHI) of ≥30 events/h had lower MMSE scores than those with an AHI of <15 events/h. In addition to age and education level, the severity of nocturnal intermittent hypoxia is an independent predictor of the risk of dementia in patients with COPD (OR=1.24, 95% CI 1.04-1.48, p = 0.02).

Conclusion

The current findings indicate that patients with COPD with comorbid OSA may be at greater risk for global cognitive impairment relative to patients with COPD alone. The mechanisms underlying the exaggerated cognitive dysfunction seem to be related to intermittent hypoxia. Further work is needed to understand the impact of OSA on the specific domains of cognitive impairment and the therapeutic implications of OSA in COPD.

Changes in Spatial Working Memory in Stable Chronic Obstructive Pulmonary Disease: A Retrospective Study

Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airflow limitation and is often accompanied by cognitive impairment. Little is known about the working memory of COPD patients. The aim of the study is to evaluate the spatial working memory of COPD patients using the classical visuospatial working memory neuropsychological paradigms. This was a retrospective study of patients with COPD who were evaluated for neurocognitive functions between February and December 2018 at Hefei Second People's Hospital. Healthy controls (HC) were included. The neuropsychological tests included the Beijing Version of the Montreal Cognitive Assessment Test (MoCA), digit span test (DS), Chinese Auditory Verbal Learning Test (CAVLT), Stroop test, and Verbal Fluency Test (VFT). The COPD group performed worse in MoCA (22.3 ± 4.5 vs. 26.1 ± 2.9, P < 0.001), Stroop interference test (44.2 ± 16.9 vs. 36.8 ± 10.3, P = 0.038), and VFT (12.9 ± 2.8 vs. 15.3 ± 4.7, P = 0.021) vs. the HC group. Compared with the HC group, COPD patients had statistically significant differences with respect to 0-back RT (657 ± 46 vs. 578 ± 107, P = 0.001), 1-back accuracy (41.8 ± 12.1% vs. 81.5 ± 18.1%, P < 0.001), 1-back RT (592 ± 75 vs. 431 ± 138, P < 0.001), 2-back accuracy (31.4 ± 9.9% vs. 68.1 ± 16.6%, P < 0.001), and 2-back RT (563 ± 79 vs. 455 ± 153, P = 0.002). Only PaO₂ was independently associated with 0-back RT (B = 0.992 ± 0.428, P = 0.028) and 1-back ACC (B = 0.003 ± 0.001, P = 0.004). COPD patients exhibit impairment in working memory and executive function, but not in short- or long-term memory. The impairment of working memory in a patient with COPD may be more due to integrate memory information rather than to memory information storage. COPD patients exhibit a frontal-type cognitive decline.

Management of the COPD Patient with Comorbidities: An Experts Recommendation Document

Background

Chronic obstructive pulmonary disease (COPD) is associated with multiple comorbidities, which impact negatively on patients and are often underdiagnosed, thus lacking a proper management due to the absence of clear guidelines.

Purpose

To elaborate expert recommendations aimed to help healthcare professionals to provide the right care for treating COPD patients with comorbidities.

Methods

A modified RAND-UCLA appropriateness method consisting of nominal groups to draw up consensus recommendations (6 Spanish experts) and 2-Delphi rounds to validate them (23 Spanish experts) was performed.

Results

A panel of Spanish internal medicine experts reached consensus on 73 recommendations and 81 conclusions on the clinical consequences of the presence of comorbidities. In general, the experts reached consensus on the issues raised with regard to cardiovascular comorbidity and metabolic disorders. Consensus was reached on the use of selective serotonin reuptake inhibitors in cases of depression and the usefulness of referring patients with anxiety to respiratory rehabilitation programmes. The results also showed consensus on the usefulness of investigating the quality of sleep, the treatment of pain with opioids and the evaluation of osteoporosis by lateral chest radiography.

Conclusion

This study provides conclusions and recommendations that are intended to improve the management of the complexity of patients with COPD and important comorbidities, usually excluded from clinical trials.

The association of cognitive functioning as measured by the DemTect with functional and clinical characteristics of COPD: results from the COSYCONET cohort

Alterations of cognitive functions have been described in COPD. Our study aimed to disentangle the relationship between the degree of cognitive function and COPD characteristics including quality of life (QoL).

Data from 1969 COPD patients of the COSYCONET cohort (GOLD grades 1–4; 1216 male/ 753 female; mean (SD) age 64.9 ± 8.4 years) were analysed using regression and path analysis. The DemTect screening tool was used to measure cognitive function, and the St. George‘s respiratory questionnaire (SGRQ) to assess disease-specific QoL.

DemTect scores were < 9 points in 1.6% of patients and < 13 points in 12% when using the original evaluation algorithm distinguishing between < 60 or > =60 years of age. For statistical reasons, we used the average of both algorithms independent of age in all subsequent analyses. The DemTect scores were associated with oxygen content, 6-min-walking distance (6-MWD), C-reactive protein (CRP), modified Medical Research Council dyspnoea scale (mMRC) and the SGRQ impact score. Conversely, the SGRQ impact score was independently associated with 6-MWD, FVC, mMRC and DemTect. These results were combined into a path analysis model to account for direct and indirect effects. The DemTect score had a small, but independent impact on QoL, irrespective of the inclusion of COPD-specific influencing factors or a diagnosis of cognitive impairment.

We conclude that in patients with stable COPD lower oxygen content of blood as a measure of peripheral oxygen supply, lower exercise capacity in terms of 6-MWD, and higher CRP levels were associated with reduced cognitive capacity. Furthermore, a reduction in cognitive capacity was associated with reduced disease-specific quality of life. As a potential clinical implication of this work, we suggest to screen especially patients with low oxygen content and low 6-MWD for cognitive impairment.

Memory, attention and fluency deficits in COPD may be a specific form of cognitive impairment

There is increasing evidence demonstrating an association between chronic obstructive pulmonary disease (COPD) and cognitive impairment. We present a narrative review of published studies on the subject and a cross-sectional study investigating domain-specific cognitive impairment in people with COPD compared to people with known Alzheimer's dementia, and controls without known COPD or cognitive impairment. The aim of the study was to compare prevalence and pattern of cognitive impairment between the three groups using the Addenbrooke's Cognitive Examination (ACE)-III tool.

A total of 89 participants were recruited (44 with COPD, 17 with Alzheimer's and 28 controls).

Patients with COPD had significantly lower total ACE-III scores than controls (p<0.001). When comparing the COPD group to the known Alzheimer's dementia group, overall ACE-III scores were significantly lower in the Alzheimer's dementia group than the COPD group (p=0.019). The domain-specific scores for attention (p<0.004), memory (p<0.004) and fluency (p<0.001) were significantly lower in the Alzheimer's dementia group than the COPD group.

Our result suggest that the COPD group were significantly more likely to have cognitive impairment than the healthy control group. This was supported by the results of a narrative review of the published literature. Our results show that the pattern of impairment in the COPD group is different to the pattern of impairment shown in the known Alzheimer's dementia group, with significant differences in the cognitive domains affected. These results are in keeping with the findings of other previously published studies included in the narrative review.

People with COPD are more likely than controls to have cognitive impairment. When compared to people with known Alzheimer's disease, the pattern of impairment and cognitive domains affected are significantly different.http://bit.ly/2VPFxjh

Effects of health literacy and cognitive abilities on COPD self-management behaviors: A prospective cohort study

INTRODUCTION

Low rates of adherence to self-management behaviors are common among patients with COPD. Health literacy and cognitive abilities may influence engagement in self-management behaviors. We sought to assess the association between health literacy and cognitive abilities with self-management behaviors in patients with COPD.

METHODS

We conducted an observational cohort study among American adults with COPD in New York, New York, and Chicago, Illinois. Outcomes included adherence to COPD medication, metered dose inhaler (MDI) and dry powder inhaler (DPI) technique, receipt of vaccination, and routine healthcare appointments. Health literacy was measured with the Short Test of Functional Health Literacy in Adults. Cognitive function was assessed in terms of global, fluid (working memory, processing speed, executive function) and crystallized (verbal) ability.

RESULTS

Adequate health literacy was associated with adequate adherence to COPD medications (OR 1.46; 95% CI, 1.02-2.08), correct MDI (OR 1.66; 95% CI, 1.13-2.44) and DPI (OR 2.17; 95% CI, 1.30-3.64) technique. Fluid abilities were also associated with medication behaviors and visiting a regular healthcare provider, while crystalized abilities were not. Global cognitive abilities were associated with correct inhaler technique. No other associations were found with non-medication self-management behaviors.

CONCLUSIONS

COPD patients with limited health literacy and deficits in fluid cognitive abilities have lower rates of adherence and poorer inhaler technique than individuals with adequate health literacy and greater fluid cognitive abilities. These findings highlight the importance of considering the health literacy level and cognitive ability when caring for and educating patients with COPD.

COPD and the risk of mild cognitive impairment and dementia: a cohort study based on the Chinese Longitudinal Health Longevity Survey

Background

COPD may lead to cognitive impairment or even dementia. However, the current conclusions are inconsistent with little evidence from prospective, large-sample studies. This study was designed to explore the association of COPD with mild cognitive impairment (MCI) and dementia risk based on a cohort study.

Patients and methods

All participants were from the Chinese Longitudinal Health Longevity Survey (CLHLS) 2011/2012 waves. The follow-up survey was conducted in 2014 and the incidence of MCI and dementia were recorded.

Results

During the 3-year follow-up period, 712 new cases of MCI and 83 new cases of dementia were diagnosed. The incidence of MCI and dementia were higher in those with COPD than those without COPD at baseline. Cox analysis showed that the HRs of COPD for MCI and dementia incidence were 1.486 (95% CI: 1.207-1.855) and 1.896 (95% CI: 1.079-3.330), respectively after adjusting for related covariates. For different baseline smoking status, those who were current smokers had the highest HRs of COPD for MCI and dementia.

Conclusion

Baseline COPD was independently associated with increased risk of MCI and dementia incidence among Chinese elderly, and the association was more pronounced among those who were current smokers.

Neurocognitive and behavioral abnormalities in Indian children with sleep-disordered breathing before and after adenotonsillectomy

Objectives:

Children with untreated sleep-disordered breathing (SDB) have impaired intellectual ability and behavioral effects. Timely treatment of SDB by adenotonsillectomy (AT) may prevent this morbidity. This study was designed to assess the prevalence of neurocognitive and behavioral dysfunction in Indian children with SDB and to evaluate the impact of AT.

Methods:

Children recruited underwent diagnostic polysomnography (PSG), a detailed neurocognitive and behavioral assessment using a battery of validated instruments – the Malin's Intelligence Scale (MIS) for Indian children, Modified Wisconsin's Card Sorting Test, Parent Conners' Scale, and the Childhood Behavior Checklist (6–18). These children then underwent AT and subsequent reassessment at 3 and 6 months.

Results:

Neurocognitive impairment was common among the 33 enrolled children (mean age 9 [±2.97] years; 78.8% males). There was a significant correlation between the lowest O₂ saturation and the “categories completed” (r = -0.379; P = 0.029); and the lowest O₂ saturation and the “failure to maintain sets” (r = 0.386; P = 0.026) of the Modified Wisconsin's Card Sorting Test. Postsurgery, although apnea–hypopnea index (AHI) significantly decreased after surgery, 15 children still had SDB. Mean scores of most of the tested neurocognitive and behavioral domains showed improvement, although residual deficits were prevalent even after 6 months. Patients with a baseline AHI >5/h and those who had complete resolution of SDB (postoperative AHI <1/h) showed improvement in more subscales than patients with baseline AHI < 5/h and patients with incomplete resolution of SDB.

Conclusion:

The decreased neurocognitive performance related to SDB may be a result of hypoxemia, rather than the frequency of SDB events. Despite AT, residual disease is common and such patients may require further treatment.

Epidemiology of Dementia in Elderly Chronic Obstructive Pulmonary Disease Patients Living in China's Northwestern High-Elevation Area

Background

The aim of this study was to investigate the effects of oxygen and cholinesterase inhibitor (donepezil) therapy on dementia in patients with age-exacerbated chronic obstructive pulmonary disease (COPD) in China’s northwestern high-altitude area.

Material/Methods

A total of 145 patients with acute exacerbation of COPD admitted to the Gerontology Department of the First People’s Hospital of Xining City were initially retrospectively screened. From among these 145 patients, we selected 33 cases with dementia and 33 patients without dementia through use of the Mini-Mental State Examination (MMSE), the Alzheimer’s Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), and Activities of Daily Living (ADL) Scale evaluated before, 7 days after, and at the end of the treatment after 3 months. Both patient groups received oxygen therapy for 7 days, but patients with dementia in the intervention group were medicated additionally with donepezil (5 mg/day for 1 week, followed by 10 mg/day for another 12 weeks).

Results

Mild dementia was found in 35 of the 145 COPD patients. ADL, MMSE, and ADAS-Cog scores were all significantly lower in the intervention group before treatment, improved after the first 7 days, and continued to improve significantly until week 12 in the intervention group, but were still significantly lower than in the control group.

Conclusions

Dementia in elderly COPD patients was mainly manifested as decreased executive function, attention, language, and delayed recall, while oxygen and donepezil therapy had beneficial effects on the symptoms.

Alterations of the default mode network and cognitive impairments in patients with chronic obstructive pulmonary disease

Background and objectives

Cognitive impairment is a common extrapulmonary comorbidity in COPD patients. The default mode network (DMN) plays a critical role in maintaining the normal activities of humans, and its function can be evaluated by resting state functional magnetic resonance imaging. The aim of this study was to investigate the correlations between cognition and function changes of the DMN in COPD patients.

Methods

One hundred and thirteen eligible participants including 30 control subjects and 83 COPD patients matched for demographic characteristics were recruited. All participants performed cognitive function tests and underwent resting state functional magnetic resonance imaging.

Results

The total cognitive function scores of COPD patients were significantly different from those of control subjects (P<0.05) and worsened with the degree of airflow obstruction. The activated brain regions in the DMN of COPD patients were less than those of normal controls. Six activated brain regions in the DMN were found to develop significantly different functional connectivity (FC) values among the subjects. Meanwhile, the FC values of the left posterior cingulate cortex and left hippocampus correlated well with cognitive functions and pulmonary function.

Conclusion

COPD patients have cognitive impairments that correlate well with disease severity. FC changes in activated brain regions in the DMN may predict cognitive impairment, and the left posterior cingulate cortex and left hippocampus may be important brain regions related to cognitive impairment in COPD patients.

The relationship between cognitive function and arterial partial pressure O2 in patients with COPD: A meta-analysis

BACKGROUND

The high incidence of cognition disorders in chronic obstructive pulmonary disease (COPD) patients represents a main focus in public health field recently. Thus, we tried to explore relationship between cognitive function and arterial partial pressure O2 (PaO2) in patients with COPD as assessed by Mini-mental State Examination (MMSE) and/or Montreal Cognitive Assessment (MoCA).

MATERIALS AND METHODS

Medical and scientific literature databases, such as Web of Science, PubMed, Cochrane Library, China National Knowledge Infrastructure, and Wanfang Database, were searched independently by 2 reviewers until February 2016. Correlation coefficient (r or rs) values were obtained from each study, and 95% confidence intervals (CIs) were calculated using STATA12.0 software.

RESULTS

A total of 2049 studies were produced, and 9 of which were analyzed (714 participants) in the meta-analysis. The pooled r observed medium relationship for all selected studies (r = 0.405, 95% CI 0.31-0.55), and notable heterogeneity was also tested between studies (χ = 17.72, P = .023; I = 54.9%). After the sensitivity and subgroup analysis, the heterogeneity significantly decreased. Subgroup analysis showed that MMSE score was stronger correlation between PaO2 and cognitive function than MoCA score in the COPD patients. Begg test did not indicate potential risk of publication bias.

CONCLUSIONS

There was a negative correlation between cognitive function and anoxia in patients with COPD, so it may be extremely essential to predict and improve the status of hypoxia in COPD patients.

Neurological and Sleep Disturbances in Bronchiectasis

Bronchiectasis unrelated to cystic fibrosis is a chronic lung disease that is increasingly recognised worldwide. While other common chronic lung conditions such as chronic obstructive lung disease have been associated with cardiovascular disease, there is a paucity of data on the relationship between bronchiectasis and cardiovascular risks such as stroke and sleep disturbance. Furthermore, it is unclear whether other neuropsychological aspects are affected, such as cognition, cerebral infection, anxiety and depression. In this review, we aim to highlight neurological and sleep issues in relation to bronchiectasis and their importance to patient care.

Clinical effects of cognitive impairment in patients with chronic obstructive pulmonary disease

The aim of this study was to evaluate the clinical effects of cognitive impairment in patients with chronic obstructive pulmonary disease (COPD). A total of 91 patients with stable moderate to very severe COPD were included in this study. Cognitive functions of the patients were evaluated using the mini-mental state examination (MMSE) tool and clock-drawing test. The Brody’s Instrumental Activities of Daily Living (IADL) Questionnaire; COPD assessment test (CAT); body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE); and Charlson comorbidity index were assessed. The patients were divided into two groups as those who were diagnosed with cognitive impairment (group 1, n = 16) and those with normal cognitive functions (group 2, n = 75). Group 1 had a lower arterial partial pressure of oxygen , shorter 6-min walking distance, and higher arterial partial pressure of carbon dioxide (PaCO₂) than group 2 (p = 0.01, p = 0.024, p = 0.018, respectively). In group 1, the IADL score was lower, and CAT and BODE scores were higher than group 2 (p = 0.002, p = 0.037, p = 0.012, respectively). When we considered all the patients, there was an independent correlation between the IADL score and MMSE score (p = 0.03). This study revealed that COPD patients with cognitive impairment may have more hypoxemia and limited activities of daily living.

White matter lesions characterise brain involvement in moderate to severe chronic obstructive pulmonary disease, but cerebral atrophy does not

Background

Brain pathology is relatively unexplored in chronic obstructive pulmonary disease (COPD). This study is a comprehensive investigation of grey matter (GM) and white matter (WM) changes and how these relate to disease severity and cognitive function.

Methods

T1-weighted and fluid-attenuated inversion recovery images were acquired for 31 stable COPD patients (FEV₁ 52.1% pred., PaO₂ 10.1 kPa) and 24 age, gender-matched controls. T1-weighted images were segmented into GM, WM and cerebrospinal fluid (CSF) tissue classes using a semi-automated procedure optimised for use with this cohort. This procedure allows, cohort-specific anatomical features to be captured, white matter lesions (WMLs) to be identified and includes a tissue repair step to correct for misclassification caused by WMLs. Tissue volumes and cortical thickness were calculated from the resulting segmentations. Additionally, a fully-automated pipeline was used to calculate localised cortical surface and gyrification. WM and GM tissue volumes, the tissue volume ratio (indicator of atrophy), average cortical thickness, and the number, size, and volume of white matter lesions (WMLs) were analysed across the whole-brain and regionally – for each anatomical lobe and the deep-GM. The hippocampus was investigated as a region-of-interest. Localised (voxel-wise and vertex-wise) variations in cortical gyrification, GM density and cortical thickness, were also investigated. Statistical models controlling for age and gender were used to test for between-group differences and within-group correlations. Robust statistical approaches ensured the family-wise error rate was controlled in regional and local analyses.

Results

There were no significant differences in global, regional, or local measures of GM between patients and controls, however, patients had an increased volume (p = 0.02) and size (p = 0.04) of WMLs. In patients, greater normalised hippocampal volume positively correlated with exacerbation frequency (p = 0.04), and greater WML volume was associated with worse episodic memory (p = 0.05). A negative relationship between WML and FEV₁ % pred. approached significance (p = 0.06).

Conclusions

There was no evidence of cerebral atrophy within this cohort of stable COPD patients, with moderate airflow obstruction. However, there were indications of WM damage consistent with an ischaemic pathology. It cannot be concluded whether this represents a specific COPD, or smoking-related, effect.

Electronic supplementary material

The online version of this article (doi:10.1186/s12890-017-0435-1) contains supplementary material, which is available to authorized users.

The Relationship between Cerebral Small Vessel Disease, Hippocampal Volume and Cognitive Functioning in Patients with COPD: An MRI Study

The neural correlates of cognitive impairment in chronic obstructive pulmonary disease (COPD) are not yet understood. Structural brain abnormalities could possibly be associated with the presence of cognitive impairment through cigarette smoke, inflammation, vascular disease, or hypoxemia in these patients. This study aimed to investigate whether macrostructural brain magnetic resonance imaging (MRI) features of cerebral small vessel disease (SVD) and hippocampal volume (HCV) are related to cognitive performance in patients with COPD. A subgroup of cognitively high and low-performing COPD patients of the COgnitive-PD study, underwent a brain 3T MRI. SVD as a marker of vascular damage was assessed using qualitative visual rating scales. HCV as a marker of neurodegeneration was assessed using the learning embedding for atlas propagation (LEAP) method. Features of SVD and HCV were compared between cognitively high and low-performing individuals using Mann Whitney U tests and independent samples t-tests, respectively. No group differences were reported between 25 high-performing (mean age 60.3 (standard deviation [SD] 9.7) years; 40.0% men; forced expiratory volume in first second [FEV₁] 50.1% predicted) and 30 low-performing patients with COPD (mean age 60.6 (SD 6.8) years; 53.3% men; FEV₁ 55.6% predicted) regarding demographics, clinical characteristics, comorbidities and the presence of the SVD features and HCV. To conclude, the current study does not provide evidence for a relationship between cerebral SVD and HCV and cognitive functioning in patients with COPD. Additional studies will be needed to determine other possible mechanisms of cognitive impairment in patients with COPD, including microstructural brain changes and inflammatory-, hormonal-, metabolic- and (epi)genetic factors.

Cognitive impairment in COPD: should cognitive evaluation be part of respiratory assessment?

Cognitive impairment is highly prevalent in patients with COPD and demonstrates multiple detrimental effects on many aspects of patient state and therapeutic outcomes. It is attributed to several overlapping pathophysiological factors, with the most common being the low level of oxygen saturation due to respiratory insufficiency. Despite the impact of cognitive impairment on clinical outcomes, the screening for coexisting cognitive deficits which may interfere with the successful progress of respiratory treatment is yet neglected. There is a special consideration that cognitive deficits should be taken into account when developing respiratory therapy plans. Cognitively impaired patients are likely to require more support and have need of an individualised respiratory care plan which can also be beneficial for their cognitive deficits. Pulmonary rehabilitation as a multidisciplinary approach could be prioritised for COPD patients with cognitive impairment.

EDUCATIONAL AIMS

To illustrate the common signs of cognitive impairment and define potential associations between lung and cognitive dysfunction.To illustrate the potential influence of cognitive deficits on the optimal progress of respiratory therapy.To illustrate the importance of cognitive evaluation as part of a comprehensive clinical assessment for patients suspected of suffering cognitive impairment.

Recognition, diagnosis, and treatment of cognitive and psychiatric disorders in patients with COPD

COPD is highly prevalent and associated with substantial morbidity and mortality. Clinicians have long been aware that patients with COPD have problems with cognition and are susceptible to mood (depression) and anxiety disorders. With the increasing awareness of COPD as a multisystem disorder, many studies have evaluated the prevalence of neuropsychiatric conditions in patients with COPD. This review presents evidence regarding the prevalence of neuropsychiatric conditions (cognitive disorders/impairment, depression/anxiety) in COPD, their risk factors, and their impact on relevant outcomes. It also discusses both assessment and treatment of neuropsychiatric conditions and makes recommendations for improved screening and treatment. The findings suggest that clinicians caring for patients with COPD must become familiar with diagnosing these comorbid conditions and that future treatment has the potential to impact these patients and thereby improve COPD outcomes.

Cognitive Impairment among Patients with Chronic Obstructive Pulmonary Disease Compared to Normal Individuals

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is one of the most important causes of morbidity and mortality worldwide. The complications of COPD are numerous, and cognitive impairment is one of the most common complications that relates to mortality and morbidity directly. The present study was conducted with the aim of evaluating the prevalence of cognitive impairment in patients with COPD in comparison to normal individuals.

MATERIALS AND METHODS

In this case-control study, 87 patients with COPD, whose diagnoses were confirmed by a pulmonologist based on the spirometry test findings, were included. The mini-mental state examination (MMSE) questionnaire was administered for assessing the cognitive impairment. Arterial oxygen saturation was measured. The MMSE questionnaires were administered to 60 healthy, age-and-sex-matched individuals without a history of myocardial infarction or cerebrovascular infarction, and their arterial oxygen saturations were measured. The data were analyzed using the SPSS (version 20) software.

RESULTS

In the case group, 42 patients (48.27%) had no cognitive impairment, 39 (44.82%) had mild, and 6 (6.89%) had moderate cognitive impairment. In the control group, 38 (63.33%) had no cognitive impairment, 20 (33.33%) mild and 2 (3.33 %) moderate cognitive impairment. There were significant relationships between the cognitive impairment and arterial oxygen saturation, severity of COPD, and higher age. The prevalence of cognitive impairment was 51.71% in the case group and 36.66% in the control group.

CONCLUSION

According the results of the present study, COPD increased the risk of cognitive impairment significantly and is related to the severity of COPD, arterial oxygen saturation, and higher age.

Domain-specific cognitive impairment in patients with COPD and control subjects

Impaired cognitive function is increasingly recognized in COPD. Yet, the prevalence of cognitive impairment in specific cognitive domains in COPD has been poorly studied. The aim of this cross-sectional observational study was to compare the prevalence of domain-specific cognitive impairment between patients with COPD and non-COPD controls. A neuropsychological assessment was administered in 90 stable COPD patients and 90 non-COPD controls with comparable smoking status, age, and level of education. Six core tests from the Maastricht Aging Study were used to assess general cognitive impairment. By using Z-scores, compound scores were constructed for the following domains: psychomotor speed, planning, working memory, verbal memory, and cognitive flexibility. General cognitive impairment and domain-specific cognitive impairment were compared between COPD patients and controls after correction for comorbidities using multivariate linear and logistic regression models. General cognitive impairment was found in 56.7% of patients with COPD and in 13.3% of controls. Deficits in the following domains were more often present in patients with COPD after correction for comorbidities: psychomotor speed (17.8% vs 3.3%; P<0.001), planning (17.8% vs 1.1%; P<0.001), and cognitive flexibility (43.3% vs 12.2%; P<0.001). General cognitive impairment and impairments in the domains psychomotor speed, planning, and cognitive flexibility affect the COPD patients more than their matched controls.

Guiding Principles for the Use of Nebulized Long-Acting Beta2-Agonists in Patients with COPD: An Expert Panel Consensus

Determining which patients with COPD may benefit from a nebulized long-acting beta2-agonist (LABA) is a challenge in current practice. In the absence of strong clinical guidelines addressing this issue, an expert panel convened to develop guiding principles for the use of nebulized LABA therapy in patients with COPD. This article summarizes these guiding principles and other practical issues discussed during a roundtable meeting.

Airflow limitation as a risk factor for low bone mineral density and hip fracture

AIM

To investigate whether airflow limitation is associated with bone mineral density (BMD) and risk of hip fractures.

METHODS

A community sample of 5,100 subjects 47-48 and 71-73 years old and living in Bergen was invited. Participants filled in questionnaires and performed a post-bronchodilator spirometry measuring forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC). All attendants were invited to have a BMD measurement of the hip. During 10 years of follow-up, information on death was collected from the Norwegian Cause of Death Registry, and incident hip fractures were registered from regional hospital records of discharge diagnoses and surgical procedure codes.

RESULTS

The attendance rate was 69% (n=3,506). The prevalence of chronic obstructive pulmonary disease (COPD) (FEV1/FVC<0.7) was 9%. In multiple logistic regression, the lowest quartile of BMD versus the three upper was significantly predicted by FEV1/FVC<0.7 and FEV1% predicted (odds ratio [OR]: 1.58, 95% confidence interval [CI]: 1.11 to 2.25, and OR per increase of 10%: 0.92, 95% CI: 0.86 to 0.99, respectively). Hip fracture occurred in 126 (4%) participants. In a Cox regression analysis, FEV1% predicted was associated with a lowered risk of hip fracture (hazard ratio per increase of 10%: 0.89, 95% CI: 0.79 to 0.997).

CONCLUSION

Airflow limitation is positively associated with low BMD and risk of hip fracture in middle-aged and elderly.

Sleep quality disturbances and cognitive functioning in elderly patients with COPD

Information about the association between cognitive functions, such as copying function, and sleep disturbances in patients with chronic obstructive pulmonary disease (COPD) is lacking. This cross-sectional observational study aimed to investigate the association between copying function and self-reported sleep quality disturbances and disease severity in an elderly COPD population.

Cognitive function performances, assessed using the Mini-Mental State Examination, were compared in 562 ambulatory COPD patients with and without sleep disturbances; assessed using the Established Populations for Epidemiologic Studies of the Elderly questionnaire; and stratified by Global Initiative for Chronic Obstructive Lung Disease (GOLD) grades.

Sleep disturbances overall were not correlated with cognitive functioning. A trend was revealed towards worse design copying in patients with sleep disturbances overall. GOLD I patients with difficulties falling asleep and nocturnal awakenings had worse copying ability compared to GOLD I patients without these sleep disturbances. Copying ability was worse for GOLD III than GOLD I, orientation was worse for GOLD II than GOLD I and language was worse for GOLD II and III than GOLD I.

To conclude, sleep disturbances seem to be a weak correlate of cognitive functioning, and are not a marker of disease severity.

Sleep disturbances are a weak correlate of cognitive functioning in COPDhttp://ow.ly/gUhD301PvcQ

Alteration of spontaneous brain activity in COPD patients

Background and objective

Airflow limitation in chronic obstructive pulmonary disease (COPD) results in a decrease in oxygen transport to the brain. The aim of the present study was to explore the alteration of spontaneous brain activity induced by hypoxia in patients with COPD.

Patients and methods

Twenty-five stable patients with COPD and 25 matching healthy volunteers were investigated. Amplitude of low-frequency fluctuation (ALFF) of blood oxygenation level-dependent signal at resting state in the brain was analyzed using functional magnetic resonance imaging.

Results

Whole-brain analysis using functional magnetic resonance imaging revealed significant decreases in ALFF in the bilateral posterior cingulate gyri and right lingual gyrus and an increase in ALFF in the left postcentral gyrus of patients with COPD. After controlling for SaO₂, patients with COPD only showed an increase in ALFF in the left postcentral gyrus. Region of interest analysis showed a decrease in ALFF in the left precentral gyrus and an increase in ALFF in the left caudate nucleus of patients with COPD. In all subjects, ALFF in the bilateral posterior cingulate gyri and right lingual gyrus showed positive correlations with visual reproduction.

Conclusion

We demonstrated abnormal spontaneous brain activity of patients with COPD, which may have a pathophysiologic meaning.

Executive Function, Survival, and Hospitalization in Chronic Obstructive Pulmonary Disease. A Longitudinal Analysis of the National Emphysema Treatment Trial (NETT)

RATIONALE

Cognitive dysfunction has been demonstrated in chronic obstructive pulmonary disease (COPD), but studies are limited to cross-sectional analyses or incompletely characterized populations.

OBJECTIVES

We examined longitudinal changes in sensitive measures of executive function in a well-characterized population of patients with severe COPD.

METHODS

This study was performed on patients enrolled in the National Emphysema Treatment Trial. To assess executive function, we analyzed trail making (TM) A and B times at enrollment in the trial (2,128 patients), and at 12 (731 patients) and 24 months (593 patients) after enrollment, adjusted for surgery, marriage status, age, education, income, depression, PaO2, PaCO2, and smoking. Associations with survival and hospitalizations were examined using Cox regression and linear regression models.

MEASUREMENTS AND MAIN RESULTS

The average age of the patients was 66.4 years, and the average FEV1 was 23.9% predicted. At the time of enrolment, 38% had executive dysfunction. Compared with those who did not, these patients were older, less educated, had higher oxygen use, higher PaCO2, worse quality of life as measured by the St. George's Respiratory Quotient, reduced well-being, and lower social function. There was no significant change over 2 years in TM A or B times after adjustment for covariables. Changes in TM B times were modestly associated with survival, but changes in TM B-A times were not. Changes in TM scores were not associated with frequency of hospitalization. Lung function, PaO2, smoking, survival, and hospitalizations were not significantly different in those with executive dysfunction.

CONCLUSIONS

In this large population of patients with severe emphysema and heavy cigarette smoking exposure, there was no significant decline over 2 years in cognitive executive function as measured by TM tests. There was no association between executive function impairment and frequency of hospitalization, and there was a possible modest association with survival. It is plausible that cerebrovascular comorbidities explain previously described cognitive pathology in COPD.

Erratum to: Safety Considerations of Inhaled Corticosteroids in the Elderly

Inhaled corticosteroids (ICSs) are widely used in the treatment of patients with chronic obstructive pulmonary diseases. However, high-dose regimens and long-term use of ICSs have the potential to cause a variety of local and systemic side effects such as candidiasis, cataracts, glaucoma, and osteoporosis. The use of ICSs can also be associated with the risk of bone fractures, diabetes mellitus and pneumonia. These ICS-related side effects are of particular importance in elderly patients due to the presence of comorbidities and age-related behavioral, cognitive, and psychological problems, which can all interact with inhaled treatment. We reviewed the available literature on the clinically relevant side effects of ICSs in the elderly to provide practical measures to properly monitor and manage the risk of ICSs in the geriatric population. Inspection of the mouth, monitoring of ocular pressure, and use of bone-protective drugs may be necessary in patients on prolonged ICS therapy. Above all, the use of the lowest possible ICS dose and a careful re-assessment of the inhalation procedure should be recommended. Taken together, these observations suggest that physicians should use ICSs appropriately for those patients in whom the benefit will outweigh the risk, especially chronic obstructive pulmonary disease (COPD) patients with previous frequent exacerbations. Given the paucity of information on the topic and the need to extrapolate the results from studies with broader age ranges, we strongly encourage the design of specifically tailored clinical studies in the elderly.

Cognitive status among patients with chronic obstructive pulmonary disease

PURPOSE

We investigated the association between cognitive impairment and chronic obstructive pulmonary disease (COPD), taking into account demographic and clinical variables evaluated during routine practice.

PATIENTS AND METHODS

We performed a post hoc analysis of a cross-sectional study that included subjects with stable COPD. Sociodemographic and clinical information was recorded using the Body mass index, airflow Obstruction, Dyspnea and Exacerbations index and the Charlson comorbidity index. Cognitive performance was studied by the mini-mental state examination, with a score less than 27 indicating clinical impairment. Depressive symptoms, physical activity, and quality of life (EuroQoL-5 dimensions and COPD Assessment Test) were also evaluated.

RESULTS

The analysis included 940 subjects. The prevalence of cognitive impairment was 39.4%. Multivariate logistic regression models revealed that cognitive impairment was associated with educational level (odds ratio [OR] =0.096, 95% confidence interval [CI] =0.011-0.447) and poorer quality of life measured by the EuroQoL-5 dimensions social tariff (OR =0.967, 95% CI =0.950-0.983). When questionnaires were not included in the analysis, cognitive impairment was associated with educational level (OR =0.063, 95% CI =0.010-0.934), number of exacerbations (OR =11.070, 95% CI =1.450-84.534), Body mass index, airflow Obstruction, Dyspnea and Exacerbations index score (OR =1.261, 95% CI =1.049-1.515), and the Charlson comorbidity index (OR =1.412, 95% CI =1.118-1.783).

CONCLUSION

Cognitive impairment is common in COPD and is associated with low educational level, higher disease severity, and increased comorbidity. This could have therapeutic implications for this population.

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

Background

Previous studies suggested an association between chronic obstructive pulmonary disease (COPD) and cognitive impairment, mostly in developed countries. There is no evidence available on the association between these two common chronic disorders in the elderly people in People’s Republic of China where the population is aging rapidly.

Methods

The study population was randomly selected from a nationally representative Disease Surveillance Point System in People’s Republic of China. A standardized questionnaire was administered by trained interviewers during a face-to-face interview in the field survey conducted in 2010–2011. Cognitive function was assessed using the Mini-Mental State Examination. COPD was measured by self-report and the Medical Research Council respiratory questionnaire was used to assess respiratory symptoms. A multivariate logistic regression model was applied to examine the association between COPD and cognitive impairment with adjustment for potential confounding factors.

Results

A total of 16,629 subjects aged over 60 years were included in the study. The prevalence of cognitive impairment was 9.4% (95% confidence interval [CI] 7.7, 11.1). Chronic phlegm was associated with significantly higher prevalence of cognitive impairment in models adjusted for age, sex, marital status, geographic region, urban/rural, education, smoking status, alcohol drinking, and indoor air pollution (odds ratio [OR] 1.46, 95% CI 1.11, 1.93). Chronic respiratory symptoms and self-reported COPD were strongly related to cognitive impairment in urban areas. There were no significant effect modifications for sex, regions, educational level, smoking status, and alcohol drinking.

Conclusion

There was strong association between COPD and cognitive impairment in urban Chinese elderly population.

Chronic obstructive pulmonary disease associated with increased risk of bipolar disorder

Epidemiological studies have identified a trend in the development of depressive and anxiety disorders following a diagnosis of chronic obstructive pulmonary disease (COPD). However, the relationship between COPD and subsequent bipolar disorder remains unclear. From January 1, 2000, we identified adult patients with COPD from the Taiwan National Health Insurance Research Database. A nationwide population-based study was conducted; 46,778 COPD patients and 46,778 age-, sex-, and comorbidity-matched subjects between 2000 and 2011 were enrolled. The two cohorts were followed up till December 31, 2011 and observed for occurrence of bipolar disorder. We observed the COPD and comparison cohorts for 263,020 and 267,895 person-years, respectively, from 2000 to 2011. The incidence rate for bipolar disorder was 1.6/1000 person-years in the COPD cohort and 1.2/1000 person-years in the comparison cohort ( p < 0.001). After multivariate adjustment, the hazard ratio (HR) for subsequent bipolar disorder among the COPD patients was 1.42 (95% confidence interval [CI], 1.22-1.64; p < 0.001). In the COPD patients, short-acting beta-agonists (SABAs) was associated with a significantly increased risk of bipolar disorder development (HR = 1.83, 95% CI = 1.25-2.69, p = 0.002). Other COPD medications were not associated with the risk of bipolar disorder development. The study results indicate that COPD may be an independent risk factor for the development of bipolar disorder. The regular use of SABAs might increase the risk of bipolar disorder in COPD patients.

Assessment of cognitive impairment in long-term oxygen therapy-dependent COPD patients

BACKGROUND

A number of studies have shown that COPD, particularly in its later and more severe stages, is associated with various cognitive deficits. Thus, the primary goal of the present study was to elucidate the extent of cognitive impairment in patients with long-term oxygen therapy-dependent (LTOTD) COPD. In addition, this study aimed to determine the effectiveness of two cognitive screening tests, the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA), for COPD patients and the ability of oxygen therapy to mitigate COPD-related deficits in cognitive function.

METHODS

The present study enrolled 45 subjects: 24 nonuser and 21 regular-user LTOTD-COPD patients. All subjects had a similar grade of education, and there were no significant differences regarding age or sex. The MoCA (cutoff: <26 points) and MMSE (cutoff: ≤24 points) scores were compared between these two groups.

RESULTS

The nonuser LTOTD-COPD group had a significantly lower MoCA score than that of the regular-user LTOTD-COPD group (19.38±2.99 vs 21.68±2.14, respectively) as well as a significantly lower MMSE score. Moreover, the absence of supplemental oxygen therapy increased the risk of cognitive impairment (MoCA, P=0.007 and MMSE, P=0.014), and the MoCA and MMSE scores significantly correlated with the number of emergency admissions and the number of hospitalizations in the last year.

CONCLUSION

In the present study, the nonuser LTOTD-COPD group exhibited a significant decrease in cognitive status compared with the regular-user LTOTD-COPD group. This suggests that the assessment of cognitive function in nonuser LTOTD-COPD patients and the use of protective strategies, such as continuous supplemental oxygen treatment, should be considered during the management of COPD in this population. In addition, the MoCA score was superior to the MMSE score for the determination of cognitive impairment in the nonuser LTOTD-COPD patients.

Safety considerations of inhaled corticosteroids in the elderly

Inhaled corticosteroids (ICSs) are widely used in the treatment of patients with chronic obstructive pulmonary diseases. However, high-dose regimens and long-term use of ICSs have the potential to cause a variety of local and systemic side effects such as candidiasis, cataracts, glaucoma, and osteoporosis. The use of ICSs can also be associated with the risk of bone fractures, diabetes mellitus and pneumonia. These ICS-related side effects are of particular importance in elderly patients due to the presence of comorbidities and age-related behavioral, cognitive, and psychological problems, which can all interact with inhaled treatment. We reviewed the available literature on the clinically relevant side effects of ICSs in the elderly to provide practical measures to properly monitor and manage the risk of ICSs in the geriatric population. Inspection of the mouth, monitoring of ocular pressure, and use of bone-protective drugs may be necessary in patients on prolonged ICS therapy. Above all, the use of the lowest possible ICS dose and a careful re-assessment of the inhalation procedure should be recommended. Taken together, these observations suggest that physicians should use ICSs appropriately for those patients in whom the benefit will outweigh the risk, especially chronic obstructive pulmonary disease (COPD) patients with previous frequent exacerbations. Given the paucity of information on the topic and the need to extrapolate the results from studies with broader age ranges, we strongly encourage the design of specifically tailored clinical studies in the elderly.

Cognitive impairment in COPD: a systematic review

The objectives of this study were to characterize and clarify the relationships between the various cognitive domains affected in COPD patients and the disease itself, as well as to determine the prevalence of impairment in the various cognitive domains in such patients. To that end, we performed a systematic review using the following databases: PubMed, Scopus, and ScienceDirect. We included articles that provided information on cognitive impairment in COPD patients. The review of the findings of the articles showed a significant relationship between COPD and cognitive impairment. The most widely studied cognitive domains are memory and attention. Verbal memory and learning constitute the second most commonly impaired cognitive domain in patients with COPD. The prevalence of impairment in visuospatial memory and intermediate visual memory is 26.9% and 19.2%, respectively. We found that cognitive impairment is associated with the profile of COPD severity and its comorbidities. The articles reviewed demonstrated that there is considerable impairment of the cognitive domains memory and attention in patients with COPD. Future studies should address impairments in different cognitive domains according to the disease stage in patients with COPD.

Associations between sleep-disordered breathing, nocturnal hypoxemia, and subsequent cognitive decline in older community-dwelling men: the Osteoporotic Fractures in Men Sleep Study

OBJECTIVES

To determine whether sleep-disordered breathing (SDB), a group of disorders common in older adults characterized by breathing pauses during sleep often accompanied by hypoxemia, is associated with cognitive decline.

DESIGN

Population-based longitudinal study.

SETTING

Six centers in the United States.

PARTICIPANTS

Community-dwelling older men (N=2,636; aged 76.0±5.3) without probable mild cognitive impairment or dementia followed for 3.4±0.5 years.

MEASUREMENTS

SDB was measured using in-home polysomnography: nocturnal hypoxemia (≥1% of sleep time with oxygen saturation (SaO2)<90%, oxygen desaturation index (ODI: number of oxygen desaturations of ≥3% per hour of sleep)) and apnea-hypopnea index (AHI, number of apneas and hypopneas at ≥3% desaturation per hour of sleep). Cognitive decline was measured using the Modified Mini-Mental State Examination (3MS) and the Trail-Making Test Part B (Trails B) at baseline and two follow-up points. Associations between predictors and cognitive decline were examined using linear mixed models adjusted for multiple confounders. Models were further adjusted for potential mediators (sleep duration, sleep fragmentation, resting SaO2).

RESULTS

Nocturnal hypoxemia was related to greater decline on the 3MS. Men with 1% or more of sleep time with SaO2 less than 90% had an adjusted annualized decline of 0.43 points, compared with 0.25 for men in the reference group (P=.003). For each 5-point increase in ODI, there was an average annualized decline of 0.36 points (P=.01). Results were robust to further adjustment for potential mediators. The association between AHI and cognitive decline did not reach significance. No associations were seen with SDB and decline on the Trails B.

CONCLUSION

In older community-dwelling men, there was a modest association between nocturnal hypoxemia and global cognitive decline, suggesting the importance of overnight oxygenation for cognitive function.

COPD is associated with cognitive dysfunction and poor physical fitness in heart failure

OBJECTIVE

To examine the associations among chronic obstructive pulmonary disease (COPD), cognitive function, and physical fitness in heart failure (HF).

BACKGROUND

Cognitive impairment in HF in part stems from medical comorbidities and poor physical fitness. COPD, a frequent co-existing condition in HF, is a risk factor for cognitive impairment and a known cause of poor physical fitness. Yet, the interplay among COPD, cognition, and physical fitness has never been examined in HF.

METHODS

191 HF patients completed a cognitive test battery and brief physical fitness assessment. Diagnostic history of COPD was ascertained via medical chart review.

RESULTS

Regression analyses showed HF patients with COPD exhibited worse attention/executive function and poorer fitness relative to their non-COPD counterparts. Worse fitness correlated with cognitive dysfunction.

CONCLUSIONS

COPD is associated with reduced cognition and worse fitness in HF. Longitudinal work that employs objective assessments of COPD is needed to determine directionality and clarify mechanisms.

Protective effect of Dl-3n-butylphthalide on learning and memory impairment induced by chronic intermittent hypoxia-hypercapnia exposure

Cognitive impairment is a common finding in patients with chronic obstructive pulmonary disease (COPD), but little attention has been focused on therapeutic intervention for this complication. Chronic intermittent hypoxia hypercapnia (CIHH) exposure is considered to be responsible for the pathogenesis of COPD. Dl-3n-Butylphthalide (NBP), extracted from Apium graveolens Linn, has displayed a broad spectrum of neuroprotective properties. Our study aimed to investigate the potential of NBP on CIHH-induced cognitive deficits. The cognitive function of rats after CIHH exposure was evaluated by the Morris water maze, which showed that the NBP treated group performed better in the navigation test. NBP activated BDNF and phosphorylated CREB, the both are responsible for neuroprotection. Additionally, NBP decreased CIHH induced apoptosis. Moreover, NBP further induced the expression of HIF-1α, accompanied by the up-regulation of the autophagy proteins Bnip3, Beclin-1 and LC3-II. Finally, NBP also reversed the decreased expression of SIRT1 and PGC-1α, but the expression of Tfam, Cox II and mtDNA remained unchanged. These results suggested that the neuroprotective effects of NBP under CIHH condition possibly occurred through the inhibition of apoptosis, promotion of hypoxia-induced autophagy, and activation of the SIRT1/PGC-1α signalling pathway, while stimulation of mitochondrial biogenesis may not be a characteristic response.

COgnitive-pulmonary disease

Over the past few decades, chronic obstructive lung disease (COPD) has been considered a disease of the lungs, often caused by smoking. Nowadays, COPD is regarded as a systemic disease. Both physical effects and effects on brains, including impaired psychological and cognitive functioning, have been demonstrated. Patients with COPD may have cognitive impairment, either globally or in single cognitive domains, such as information processing, attention and concentration, memory, executive functioning, and self-control. Possible causes are hypoxemia, hypercapnia, exacerbations, and decreased physical activity. Cognitive impairment in these patients may be related to structural brain abnormalities, such as gray-matter pathologic changes and the loss of white matter integrity which can be induced by smoking. Cognitive impairment can have a negative impact on health and daily life and may be associated with widespread consequences for disease management programs. It is important to assess cognitive functioning in patients with COPD in order to optimize patient-oriented treatment and to reduce personal discomfort, hospital admissions, and mortality. This paper will summarize the current knowledge about cognitive impairment as extrapulmonary feature of COPD. Hereby, the impact of smoking on cognitive functioning and the impact of cognitive impairment on smoking behaviour will be examined.

Effects of chronic obstructive pulmonary disease and obstructive sleep apnea on cognitive functions: evidence for a common nature

Patients with chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea syndrome (OSAS) show similar neurocognitive impairments. Effects are more apparent in severe cases, whereas in moderate and mild cases the effects are equivocal. The exact mechanism that causes cognitive dysfunctions in both diseases is still unknown and only suggestions have been made for each disease separately. The primary objective of this review is to present COPD and OSAS impact on cognitive functions. Secondly, it aims to examine the potential mechanisms by which COPD and OSAS can be linked and provide evidence for a common nature that affects cognitive functions in both diseases. Patients with COPD and OSAS compared to normal distribution show significant deficits in the cognitive abilities of attention, psychomotor speed, memory and learning, visuospatial and constructional abilities, executive skills, and language. The severity of these deficits in OSAS seems to correlate with the physiological events such as sleep defragmentation, apnea/hypopnea index, and hypoxemia, whereas cognitive impairments in COPD are associated with hypoventilation, hypoxemia, and hypercapnia. These factors as well as vascocerebral diseases and changes in systemic hemodynamic seem to act in an intermingling and synergistic way on the cause of cognitive dysfunctions in both diseases. However, low blood oxygen pressure seems to be the dominant factor that contributes to the presence of cognitive deficits in both COPD and OSAS.