Chronic obstructive pulmonary disease and association with mild cognitive impairment: the Mayo Clinic Study of Aging

To investigate the association of chronic obstructive pulmonary disease (COPD) with mild cognitive impairment (MCI) and MCI subtype: amnestic MCI and nonamnestic MCI, in a population-based study of elderly patients.

Participants included 1927 individuals aged 70 to 89 years enrolled in the population-based Mayo Clinic Study of Aging. Participants were evaluated by using a nurse assessment, neurological evaluation, and neuropsychological testing, and the diagnosis of MCI was made by a consensus panel according to the standardized criteria. Chronic obstructive pulmonary disease was identified by the review of medical records. The study was conducted from October 1, 2004, through July 31, 2007. The associations of COPD and disease duration with MCI and its subtypes were evaluated by using logistic regression models adjusted for potential covariates.

Of 1927 participants, 288 had COPD (men vs women: 18% vs 12%; P<.001). As compared with patients without COPD, patients with COPD had a higher prevalence of MCI (27% vs 15%; P<.001). The odds ratio (OR) for MCI was almost 2 times higher in patients with COPD than in those without (OR, 1.87; 95% CI, 1.34-2.61), with a similar effect in men and women. The OR for MCI increased from 1.60 (95% CI, 0.97-2.57) in patients with a COPD duration of 5 years or less to 2.10 (95% CI, 1.38-3.14) in patients with a COPD duration of more than 5 years.

This population-based study suggests that COPD is associated with increased odds of having MCI and its subtypes. There was a dose-response relationship with the duration of COPD after controlling for the potential covariates.