title: Timing of Physical Activity, Apolipoprotein E ε4 Genotype, and Risk of Incident Mild Cognitive Impairment.
abstract: To investigate the timing (mid- vs late life) of physical activity, apolipoprotein (APO)E ε4, and risk of incident mild cognitive impairment (MCI).
  
  
  
  Prospective cohort study.
  
  
  
  Mayo Clinic Study of Aging (Olmsted County, MN).
  
  
  
  Cognitively normal elderly adults (N = 1,830, median age 78, 50.2% female).
  
  
  
  Light, moderate, and vigorous physical activities in mid- and late life were assessed using a validated questionnaire. An expert consensus panel measured MCI based on published criteria. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) with age as a time scale after adjusting for sex, education, medical comorbidity, and depression.
  
  
  
  Light (HR = 0.58, 95% CI = 0.43-0.79) and vigorous (HR = 0.78, 95% CI = 0.63-0.97) physical activity in midlife were associated with lower risk of incident MCI. The association between moderate activity and incident MCI was not significant (HR = 0.85, 95% CI = 0.67-1.09). In late life, light (HR = 0.75, 95% CI = 0.58-0.97) and moderate (HR = 0.81, 95% CI = 0.66-0.99) but not vigorous physical activity were associated with lower risk of incident MCI. A synergistic interaction was also observed between mid- and late-life activity in reducing risk of incident MCI. Furthermore, APOE ε4 carriers who did not exercise had a higher risk of incident MCI than noncarriers who reported physical activity.
  
  
  
  Physical activity reduced the risk of incident MCI. Exercising in mid- and late life had an additive synergistic interaction in reducing the risk of MCI.
authors: Translational Neuroscience and Aging Program, Mayo Clinic, Scottsdale, Arizona.
authors: Janina
authors: J
authors: Krell-Roesch
authors: Translational Neuroscience and Aging Program, Mayo Clinic, Scottsdale, Arizona.
authors: Anna
authors: A
authors: Pink
authors: Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.|Department of Neurology, Mayo Clinic, Rochester, Minnesota.
authors: Rosebud O
authors: RO
authors: Roberts
authors: International Clinical Research Center, Brno, Czech Republic.
authors: Gorazd B
authors: GB
authors: Stokin
authors: Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.
authors: Michelle M
authors: MM
authors: Mielke
authors: Translational Neuroscience and Aging Program, Mayo Clinic, Scottsdale, Arizona.
authors: Kathleen A
authors: KA
authors: Spangehl
authors: Department of Neurology, Mayo Clinic, Rochester, Minnesota.
authors: Mairead M
authors: MM
authors: Bartley
authors: Department of Neurology, Mayo Clinic, Rochester, Minnesota.
authors: David S
authors: DS
authors: Knopman
authors: Division of Biomedical Statistics and Informatics, Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.
authors: Teresa J H
authors: TJ
authors: Christianson
authors: Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.|Department of Neurology, Mayo Clinic, Rochester, Minnesota.
authors: Ronald C
authors: RC
authors: Petersen
authors: Translational Neuroscience and Aging Program, Mayo Clinic, Scottsdale, Arizona.|Division of Epidemiology, Department of Health Sciences Research, Mayo Clinic, Rochester, Minnesota.|Department of Psychiatry and Psychology, Mayo Clinic, Scottsdale, Arizona.|Department of Neurology, Mayo Clinic, Scottsdale, Arizona.
authors: Yonas E
authors: YE
authors: Geda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D053327:Apolipoprotein E4 / Q000235:genetics*; D060825:Cognitive Dysfunction / Q000235:genetics* / Q000517:prevention & control*; D005260:Female; D005838:Genotype; D006801:Humans; D015994:Incidence; D008297:Male; D009043:Motor Activity; D011446:Prospective Studies; D012306:Risk; D011795:Surveys and Questionnaires
chemical_list: D053327:Apolipoprotein E4
keywords: APOE e4; mild cognitive impairment; physical activity