Inflammation-Related Proteins Are Differently Associated With Visceral Adipose Tissue, Liver Fat, and Pancreatic Fat - Abstract
Objective: Ectopic fat is associated with inflammation; whether ectopic fat in different tissues is differently associated with systemic inflammation is unclear. We compared the ectopic fat content of three tissues and investigated links with inflammation using inflammation-related proteins.
Materials and methods: Overall, 310 individuals from two trials (NCT02354976; NCT02279407) with body mass index ?25 kg/m2 and type 2 diabetes or serum triglycerides ?1.7 mmol/L were included. Magnetic resonance imaging examinations included liver proton density fat fraction (PDFF), pancreatic fat percentage, and visceral adipose tissue (VAT) volume. Total body fat mass was evaluated by bioimpedance. Plasma levels of 74 inflammation-related proteins were measured with the proximity extension assay.
Results: Proteomic profiles differed between the tissues (P<0.0001) when adjusted for age, sex, fasting glucose, and total body fat mass. Using a split sample discovery/validation approach, five proteins were significantly related to VAT and eight to liver PDFF; none were related to pancreatic fat. Fibroblast growth factor 21 and stem cell factor were related to VAT and liver PDFF. Oncostatin-M (P=0.001) was associated with VAT and the CUB domain-containing protein 1 with liver PDFF (P=0.00002).
Conclusion: Inflammation-related proteins were differently related to ectopic fat depots. Liver and visceral fat were linked to distinct inflammatory pathways; pancreatic fat was weakly linked to systemic inflammation.