title: Effect of lifestyle activities on Alzheimer disease biomarkers and cognition.
abstract: OBJECTIVE
  A study was undertaken to investigate the association of intellectual and physical activity with biomarkers of Alzheimer disease (AD) pathophysiology and cognition in a nondemented elderly population. The biomarkers evaluated were brain Aβ load via Pittsburgh compound B (PiB)-positron emission tomography (PET), neuronal dysfunction via (18) F-fluorodeoxyglucose (FDG)-PET, and neurodegeneration via structural magnetic resonance imaging (MRI).
  
  
  METHODS
  We studied 515 nondemented (428 cognitively normal and 87 mild cognitive impairment) participants in the population-based Mayo Clinic Study of Aging who completed a 3T MRI, PET scans, and APOE genotype, and had lifestyle activity measures and cognition data available. The imaging measures computed were global PiB-PET uptake, and global FDG-PET and MRI based hippocampal volume. We consolidated activity variables into lifetime intellectual, current intellectual, and current physical activities. We used a global cognitive z score as a measure of cognition. We applied 2 independent methods-partial correlation analysis adjusted for age and gender and path analysis using structural equations-to evaluate the associations between lifestyle activities, imaging biomarkers, and global cognition.
  
  
  RESULTS
  None of the lifestyle variables were correlated with the biomarkers, and the path associations between lifestyle variables and biomarkers were not significant (p > 0.05). Conversely, all the biomarkers were correlated with global cognitive z score (p < 0.05), and the path associations between (lifetime and current) intellectual activities and global z score were significant (p < 0.01).
  
  
  CONCLUSIONS
  Intellectual and physical activity lifestyle factors were not associated with AD biomarkers, but intellectual lifestyle factors explained variability in the cognitive performance in this nondemented population. This study provides evidence that lifestyle activities may delay the onset of dementia but do not significantly influence the expression of AD pathophysiology.
authors.affiliation: Department of Radiology, Mayo Clinic and Foundation, 200 First St SW, Rochester, MN 55905, USA. vemuri.prashanthi@mayo.edu
authors.forename: Prashanthi
authors.initials: P
authors.lastname: Vemuri
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Lesnick
authors.forename: Scott A
authors.initials: SA
authors.lastname: Przybelski
authors.forename: David S
authors.initials: DS
authors.lastname: Knopman
authors.forename: Rosebud O
authors.initials: RO
authors.lastname: Roberts
authors.forename: Val J
authors.initials: VJ
authors.lastname: Lowe
authors.forename: Kejal
authors.initials: K
authors.lastname: Kantarci
authors.forename: Mathew L
authors.initials: ML
authors.lastname: Senjem
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Gunter
authors.forename: Bradley F
authors.initials: BF
authors.lastname: Boeve
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Petersen
authors.forename: Clifford R
authors.initials: CR
authors.lastname: Jack
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D003072:Cognition Disorders / Q000473:pathology* / Q000523:psychology; D005260:Female; D006801:Humans; D008019:Life Style; D008279:Magnetic Resonance Imaging; D008297:Male; D008954:Models, Biological; D009043:Motor Activity; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D025341:Principal Component Analysis; D012737:Sex Factors; D013223:Statistics as Topic; D011795:Surveys and Questionnaires
chemical_list: D016229:Amyloid beta-Peptides