Physical activity, inflammation, and volume of the aging brain.
Physical activity influences inflammation, and both affect brain structure and Alzheimer's disease (AD) risk. We hypothesized that older adults with greater reported physical activity intensity and lower serum levels of the inflammatory marker tumor necrosis factor α (TNFα) would have larger regional brain volumes on subsequent magnetic resonance imaging (MRI) scans. In 43 cognitively intact older adults (79.3±4.8 years) and 39 patients with AD (81.9±5.1 years at the time of MRI) participating in the Cardiovascular Health Study, we examined year-1 reported physical activity intensity, year-5 blood serum TNFα measures, and year-9 volumetric brain MRI scans. We examined how prior physical activity intensity and TNFα related to subsequent total and regional brain volumes. Physical activity intensity was measured using the modified Minnesota Leisure Time Physical Activities questionnaire at year 1 of the study, when all subjects included here were cognitively intact. Stability of measures was established for exercise intensity over 9 years and TNFα over 3 years in a subset of subjects who had these measurements at multiple time points. When considered together, more intense physical activity intensity and lower serum TNFα were both associated with greater total brain volume on follow-up MRI scans. TNFα, but not physical activity, was associated with regional volumes of the inferior parietal lobule, a region previously associated with inflammation in AD patients. Physical activity and TNFα may independently influence brain structure in older adults.
Imaging Genetics Center, Institute for Neuroimaging and Informatics, Dept. of Neurology, Keck/USC School of Medicine, University of Southern California, Los Angeles, CA, USA.
M N
MN
Braskie
Imaging Genetics Center, Institute for Neuroimaging and Informatics, Dept. of Neurology, Keck/USC School of Medicine, University of Southern California, Los Angeles, CA, USA.
C P
CP
Boyle
Imaging Genetics Center, Institute for Neuroimaging and Informatics, Dept. of Neurology, Keck/USC School of Medicine, University of Southern California, Los Angeles, CA, USA.
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P
Rajagopalan
Imaging Genetics Center, Institute for Neuroimaging and Informatics, Dept. of Neurology, Keck/USC School of Medicine, University of Southern California, Los Angeles, CA, USA.
B A
BA
Gutman
Imaging Genetics Center, Institute for Neuroimaging and Informatics, Dept. of Neurology, Keck/USC School of Medicine, University of Southern California, Los Angeles, CA, USA.
A W
AW
Toga
Department of Radiology, University of California Los Angeles School of Medicine, Los Angeles, CA, USA.
C A
CA
Raji
Departments of Pathology, Biochemistry, and Center for Clinical and Translational Science, University of Vermont, Burlington, VT, USA.
R P
RP
Tracy
Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA.
L H
LH
Kuller
Departments of Neurology, Psychiatry, and Psychology, University of Pittsburgh, Pittsburgh, PA, USA.
J T
JT
Becker
Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA.
O L
OL
Lopez
Imaging Genetics Center, Institute for Neuroimaging and Informatics, Dept. of Neurology, Keck/USC School of Medicine, University of Southern California, Los Angeles, CA, USA; Depts. of Psychiatry, Engineering, Radiology, & Ophthalmology, Keck/USC School of Medicine, University of Southern California, Los Angeles, CA, USA. Electronic address: pthomp@usc.edu.
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PM
Thompson
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000235:genetics / Q000473:pathology* / Q000502:physiology*; D000544:Alzheimer Disease / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D001057:Apolipoproteins E / Q000235:genetics; D001921:Brain / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007249:Inflammation; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D015213:Neuroimmunomodulation; D009483:Neuropsychological Tests; D009929:Organ Size; D010296:Parietal Lobe / Q000473:pathology; D011795:Surveys and Questionnaires; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
D001057:Apolipoproteins E; D014409:Tumor Necrosis Factor-alpha
Alzheimer’s disease; MRI; exercise; inferior parietal lobule; supramarginal gyrus; tumor necrosis factor (TNFα)