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

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.