Ectopic abdominal fat measured by MRI-PDFF compared to severity of subcutaneous adipose tissue fibrosis

Motivation: Fibrosis in adipose tissue is linked to poor metabolic health but is not fully studied. Goal(s): To determine the association of MR measured liver and pancreas fat fraction (FF) and visceral fat volume (VAT) to subcutaneous fat (SAT) fibrosis overall, and by BMI, sex, and HIV infection status. Approach: The 3T MRI PDFF of the liver and pancreas, and VAT/SAT were compared to biopsy-measured hydroxyproline (a fibrosis biomarker). Results: Liver and pancreatic FF and VAT/SAT were higher with high hydroxyproline (p<0.05), particularly for those with low BMI (<25kg/m2, p<0.05) and females (p≤0.04). In HIV-positive participants, pancreatic FF was higher with high hydroxyproline (p<0.05). Impact: SAT fibrosis is associated with high liver and pancreatic fat fraction and high visceral to subcutaneous fat volume ratio, suggesting worse metabolic health, particularly for those with low BMI and for females.