Frontiers in Neuroscience (Nov 2020)

Characterization of the Meal-Stimulated Incretin Response and Relationship With Structural Brain Outcomes in Aging and Alzheimer’s Disease

  • Jill K. Morris,
  • Jill K. Morris,
  • Casey S. John,
  • Casey S. John,
  • Zachary D. Green,
  • Zachary D. Green,
  • Heather M. Wilkins,
  • Heather M. Wilkins,
  • Xiaowan Wang,
  • Xiaowan Wang,
  • Ashwini Kamat,
  • Russell S. Swerdlow,
  • Russell S. Swerdlow,
  • Eric D. Vidoni,
  • Eric D. Vidoni,
  • Melissa E. Petersen,
  • Melissa E. Petersen,
  • Sid E. O’Bryant,
  • Sid E. O’Bryant,
  • Robyn A. Honea,
  • Robyn A. Honea,
  • Jeffrey M. Burns,
  • Jeffrey M. Burns

DOI
https://doi.org/10.3389/fnins.2020.608862
Journal volume & issue
Vol. 14

Abstract

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BackgroundIndividuals with Alzheimer’s Disease (AD) are often characterized by systemic markers of insulin resistance; however, the broader effects of AD on other relevant metabolic hormones, such as incretins that affect insulin secretion and food intake, remains less clear.MethodsHere, we leveraged a physiologically relevant meal tolerance test to assess diagnostic differences in these metabolic responses in cognitively healthy older adults (CH; n = 32) and AD (n = 23) participants. All individuals also underwent a comprehensive clinical examination, cognitive evaluation, and structural magnetic resonance imaging.ResultsThe meal-stimulated response of glucose, insulin, and peptide tyrosine tyrosine (PYY) was significantly greater in individuals with AD as compared to CH. Voxel-based morphometry revealed negative relationships between brain volume and the meal-stimulated response of insulin, C-Peptide, and glucose-dependent insulinotropic polypeptide (GIP) in primarily parietal brain regions.ConclusionOur findings are consistent with prior work that shows differences in metabolic regulation in AD and relationships with cognition and brain structure.

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