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.