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

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

JOURNAL=Frontiers in Neuroscience

VOLUME=14

YEAR=2020

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2020.608862

DOI=10.3389/fnins.2020.608862

ISSN=1662-453X

ABSTRACT=<sec><title>Background</title><p>Individuals 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.</p></sec><sec><title>Methods</title><p>Here, we leveraged a physiologically relevant meal tolerance test to assess diagnostic differences in these metabolic responses in cognitively healthy older adults (CH; <italic>n</italic> = 32) and AD (<italic>n</italic> = 23) participants. All individuals also underwent a comprehensive clinical examination, cognitive evaluation, and structural magnetic resonance imaging.</p></sec><sec><title>Results</title><p>The 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.</p></sec><sec><title>Conclusion</title><p>Our findings are consistent with prior work that shows differences in metabolic regulation in AD and relationships with cognition and brain structure.</p></sec>