Motivation: Whether midlife obesity and abdominal adiposity contributes to neuroinflammation, is key to Alzheimer disease (AD) prevention. Goal(s): We aimed to investigate the association between obesity and abdominal visceral and subcutaneous adipose tissue (VAT and SAT) and neuroinflammation. Approach: For this aim, we performed brain and abdominal MRI scans to compare inflammation cellularity, edema, and axonal density using diffusion basis spectrum imaging (DBSI), between the obese vs. non-obese, the high- vs. low-VAT and high- vs. low-VAT groups. Results: A widespread higher inflammation cellularity and a lower axonal density was observed in the obese vs. non-obese, high-SAT vs. low-SAT, and high-VAT vs. low-VAT females. Impact: Higher neuroinflammation and lower axonal density in females with obesity and higher abdominal fat, highlights the sex-specific role of midlife abdominal obesity in neuroinflammation and neurodegeneration, which prompts future studies to target body fat for modifying neuroinflammation and AD prevention.

Diffusion Basis Spectrum Imaging in Midlife Obesity: Associations with Abdominal Adipose Tissue