title: Longitudinal Relationships between Caloric Expenditure and Gray Matter in the Cardiovascular Health Study.
abstract: Physical activity (PA) can be neuroprotective and reduce the risk for Alzheimer's disease (AD). In assessing physical activity, caloric expenditure is a proxy marker reflecting the sum total of multiple physical activity types conducted by an individual.
  
  
  
  To assess caloric expenditure, as a proxy marker of PA, as a predictive measure of gray matter (GM) volumes in the normal and cognitively impaired elderly persons.
  
  
  
  All subjects in this study were recruited from the Institutional Review Board approved Cardiovascular Health Study (CHS), a multisite population-based longitudinal study in persons aged 65 and older. We analyzed a sub-sample of CHS participants 876 subjects (mean age 78.3, 57.5% F, 42.5% M) who had i) energy output assessed as kilocalories (kcal) per week using the standardized Minnesota Leisure-Time Activities questionnaire, ii) cognitive assessments for clinical classification of normal cognition, mild cognitive impairment (MCI), and AD, and iii) volumetric MR imaging of the brain. Voxel-based morphometry modeled the relationship between kcal/week and GM volumes while accounting for standard covariates including head size, age, sex, white matter hyperintensity lesions, MCI or AD status, and site. Multiple comparisons were controlled using a False Discovery Rate of 5 percent.
  
  
  
  Higher energy output, from a variety of physical activity types, was associated with larger GM volumes in frontal, temporal, and parietal lobes, as well as hippocampus, thalamus, and basal ganglia. High levels of caloric expenditure moderated neurodegeneration-associated volume loss in the precuneus, posterior cingulate, and cerebellar vermis.
  
  
  
  Increasing energy output from a variety of physical activities is related to larger gray matter volumes in the elderly, regardless of cognitive status.
authors.affiliation: Department of Radiology, UCLA Medical Center, Los Angeles, CA, USA.
authors.forename: Cyrus A
authors.initials: CA
authors.lastname: Raji
authors.affiliation: Department of Psychiatry, UCLA Medical Center, Los Angeles, CA, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Merrill
authors.affiliation: Department of Nuclear Medicine, UCLA Medical Center, Los Angeles, CA, USA.|Discipline of Psychiatry, University of Adelaide, Adelaide, South Australia, Australia.
authors.forename: Harris
authors.initials: H
authors.lastname: Eyre
authors.affiliation: Department of Nuclear Medicine, UCLA Medical Center, Los Angeles, CA, USA.
authors.forename: Sravya
authors.initials: S
authors.lastname: Mallam
authors.affiliation: Department of Nuclear Medicine, UCLA Medical Center, Los Angeles, CA, USA.
authors.forename: Nare
authors.initials: N
authors.lastname: Torosyan
authors.affiliation: Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Kirk I
authors.initials: KI
authors.lastname: Erickson
authors.affiliation: Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Oscar L
authors.initials: OL
authors.lastname: Lopez
authors.affiliation: Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA.|Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.|Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: James T
authors.initials: JT
authors.lastname: Becker
authors.affiliation: Department of Neurology, University of California Davis, Davis, CA, USA.
authors.forename: Owen T
authors.initials: OT
authors.lastname: Carmichael
authors.affiliation: Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: H Michael
authors.initials: HM
authors.lastname: Gach
authors.affiliation: Department of Neurology, Laboratory of Neuro Imaging, UCLA Medical Center, Los Angeles, CA, USA.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Thompson
authors.affiliation: Department of Neurology and Epidemiology, University of Washington, Seattle, WA, USA.
authors.forename: W T
authors.initials: WT
authors.lastname: Longstreth
authors.affiliation: Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Lewis H
authors.initials: LH
authors.lastname: Kuller
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology / Q000502:physiology* / Q000523:psychology; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000503:physiopathology; D001921:Brain / Q000000981:diagnostic imaging* / Q000503:physiopathology; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging / Q000503:physiopathology; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000503:physiopathology; D015444:Exercise / Q000502:physiology*; D066128:Gray Matter / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007899:Leisure Activities; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D009929:Organ Size; D020521:Stroke / Q000000981:diagnostic imaging / Q000503:physiopathology; D014481:United States
keywords: Aging; dementia risk; energy expenditure; neuroimaging; neuroprotection; physical activity