Chronic Obstructive Pulmonary Disease and Risk of Dementia and Mortality in Lower to Middle Income Countries

Trends in prevalence and the effects on hospital outcomes of dementia in patients hospitalized with acute COPD exacerbation

AIMS

To assess changes in prevalence and the effects on hospital outcomes of dementia among patients hospitalized with an acute exacerbation of chronic obstructive pulmonary disease (AE-COPD); and to evaluate sex-differences, as well as the impact of COVID-19 pandemic in this relationship.

METHODS

We used a nationwide discharge database to select patients admitted with AE-COPD in Spain from 2011 to 2020. We identified those with any type of dementia, vascular dementia (VaD) or Alzheimer's disease (AD).

RESULTS

We identified 658,429 hospitalizations with AE-COPD (4.45% had any type of dementia, 0.79% VaD and 1.57% AD). The presence of any type of dementia remained stable from 2011 to 2015, and increased significantly between 2016 and 2020. For VaD, the time trend showed no change until 2020, when a significant increment was found. The probability of AD decreased significantly overtime. The in-hospital mortality (IHM) among patients with any type of dementia remained stable overtime until 2020, when it increased significantly. Older age, higher comorbidity, COVID-19, and use of mechanical ventilation were variables associated to IHM. Women had lower risk of dying in the hospital than men in all subgroups.

CONCLUSIONS

After a previous period of stability, the prevalence of any type of dementia increased over the last 5 years of the study, although we identified different trends depending on the specific cause of dementia. The IHM remained stable overtime until 2020, when it increased, probably related to the COVID-19 pandemic. It is remarkable the protective effect of female sex for IHM.

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 < 0.001). Subgroup analysis suggested no significant difference in the risk of dementia among COPD patients of different genders. Nevertheless, in terms of age, the risk of dementia varied among COPD patients of different ages, which was most distinguished in patients younger than 65 years.

Conclusion

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

Systematic review registration

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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