Cognitive Impairment in Chronic Obstructive Pulmonary Disease (COPD): Possible Utility of Marine Bioactive Compounds

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.

DNA damage in dementia: Evidence from patients affected by severe Chronic Obstructive Pulmonary Disease (COPD) and meta-analysis of most recent literature

Oxidative stress that leads to oxidatively damaged DNA, plays a crucial role in chronic obstructive pulmonary disease (COPD) as well as in the onset of neurodegenerative diseases. The consequent genomic instability is the first neuropathological event found in the preclinical phase of cognitive impairment (CI), and the level of DNA damage is closely related to the degree of dementia. Since CI has been associated with COPD, we investigated the extent of DNA damage in isolated lymphocytes with the Comet assay, in a group of severe COPD patients with cognitive function measured by the Mini-Mental State Examination (MMSE). An increase in DNA damage was observed in COPD patients with dementia (MMSE≤24), although the difference was only borderline (22.4 ± 6.9 vs. 18.5 ± 7.1; p = 0.055). Meta-analysis, including the results of the current study, confirmed that patients with MMSE≤ 24 showed higher level of DNA damage than patients with MMSE> 24. We observed a significant reduction (p < 0.001) in the MMSE score in patients with cognitive decline in areas I (Orientation), III (Attention and Calculus) and V (Language). Only the temporal orientation category in area I was also associated with the level of oxidative damage, with higher levels of MDA (p < 0.01) and DNA damage (p < 0.03). Patients with the lowest temporal orientation score had a 12% higher mean DNA damage (Odds Ratio=1.12; 95% confidence interval (95%CI) 1.01-1.25; p < 0.036). Temporal orientation is a component of most screening tests for the diagnosis of cognitive impairment, on the bases that disorientation is a common factor in dementia. Present results show that each component of cognitive decline can have a different etiopathogenesis and clinical relevance. A more thorough assessment of the cognitive functions of patients starting COPD rehabilitation, together with the assessment of DNA and the level of oxidative stress, can provide essential information to adapt and customize the rehabilitation project.