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

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. 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. 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. 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.