Physical activity, inflammation, and volume of the aging brain

Neuroscience. 2014 Jul 25;273:199-209. doi: 10.1016/j.neuroscience.2014.05.005. Epub 2014 May 14.

Abstract

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.

Keywords: Alzheimer’s disease; MRI; exercise; inferior parietal lobule; supramarginal gyrus; tumor necrosis factor (TNFα).

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging / genetics
  • Aging / pathology*
  • Aging / physiology*
  • Alzheimer Disease / genetics
  • Alzheimer Disease / pathology
  • Alzheimer Disease / physiopathology
  • Apolipoproteins E / genetics
  • Brain / pathology*
  • Brain / physiopathology*
  • Female
  • Humans
  • Inflammation
  • Longitudinal Studies
  • Magnetic Resonance Imaging
  • Male
  • Motor Activity / physiology*
  • Neuroimmunomodulation
  • Neuropsychological Tests
  • Organ Size
  • Parietal Lobe / pathology
  • Surveys and Questionnaires
  • Tumor Necrosis Factor-alpha / blood

Substances

  • Apolipoproteins E
  • Tumor Necrosis Factor-alpha