title: A prospective study of chronic obstructive pulmonary disease and the risk for mild cognitive impairment.
abstract: OBJECTIVE
  Previous studies suggest cross-sectional associations between a diagnosis of chronic obstructive pulmonary disease (COPD) and mild cognitive impairment (MCI). However, few studies have assessed whether COPD, a potentially modifiable factor, is associated with an increased risk for MCI and whether the relation is specific to the type of MCI.
  
  
  OBJECTIVE
  To investigate whether a diagnosis of COPD and duration of COPD are associated with an increased risk for incident MCI and MCI subtypes (amnestic MCI [A-MCI] and nonamnestic MCI [NA-MCI]).
  
  
  METHODS
  A prospective population-based cohort from the Mayo Clinic Study on Aging. We included 1425 cognitively normal individuals aged 70 to 89 years who were randomly selected from Olmsted County, Minnesota, on October 1, 2004, using the medical records linkage system. At baseline and every 15 months thereafter, participants underwent assessment with a nurse interview, neurologic examination, and neuropsychological testing. A diagnosis of COPD was confirmed via medical record review. A baseline diagnosis of COPD and duration of COPD were examined as risk factors for MCI and MCI subtypes using Cox proportional hazards models and adjusting for demographic variables and medical comorbidities, with age as the time scale.
  
  
  METHODS
  A baseline diagnosis of COPD and duration of COPD.
  
  
  METHODS
  Incident MCI, A-MCI, and NA-MCI.
  
  
  RESULTS
  Of the 1425 participants with normal cognition at baseline, 370 developed incident MCI. The median duration of follow-up was 5.1 years (interquartile range, 3.8-5.4 years). A diagnosis of COPD significantly increased the risk for NA-MCI by 83% (hazard ratio, 1.83 [95% CI, 1.04-3.23]), but not of any MCI or A-MCI in multivariate analyses. We found a dose-response relationship such that individuals with COPD duration of longer than 5 years at baseline had the greatest risk for any MCI (hazard ratio, 1.58 [95% CI, 1.04-2.40]) and NA-MCI (2.58 [1.32-5.06]).
  
  
  CONCLUSIONS
  A diagnosis of COPD is associated with an increased risk for MCI, particularly NA-MCI. We have found a dose-response relationship between COPD duration and risk for MCI. These findings highlight the importance of COPD as a risk factor for MCI and may provide a substrate for early intervention to prevent or delay the onset and progression of MCI, particularly NA-MCI.
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, Minnesota2Department of Clinical Neuroscience, University of North Dakota School of Medicine and Health Sciences, Fargo.
authors.forename: Balwinder
authors.initials: B
authors.lastname: Singh
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, Minnesota3Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.
authors.forename: Michelle M
authors.initials: MM
authors.lastname: Mielke
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, Minnesota4Department of Psychiatry and Behavior Sciences, University of Texas Medical School, Houston.
authors.forename: Ajay K
authors.initials: AK
authors.lastname: Parsaik
authors.affiliation: Division of Biomedical Statistics and Informatics, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota.
authors.forename: Ruth H
authors.initials: RH
authors.lastname: Cha
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, Minnesota3Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.
authors.forename: Rosebud O
authors.initials: RO
authors.lastname: Roberts
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Scanlon
authors.affiliation: Department of Psychiatry and Psychology, Mayo Clinic, Scottsdale, Arizona8Department of Neurology, Mayo Clinic, Scottsdale, Arizona.
authors.forename: Yonas E
authors.initials: YE
authors.lastname: Geda
authors.affiliation: Division of Biomedical Statistics and Informatics, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota.
authors.forename: Teresa J
authors.initials: TJ
authors.lastname: Christianson
authors.affiliation: Division of Biomedical Statistics and Informatics, Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota.
authors.forename: V Shane
authors.initials: VS
authors.lastname: Pankratz
authors.affiliation: Department of Neurology, Mayo Clinic, Rochester, Minnesota3Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Petersen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D060825:Cognitive Dysfunction / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D011159:Population Surveillance / Q000379:methods; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000453:epidemiology* / Q000523:psychology; D012307:Risk Factors