Biomarkers of Ectopic Fat Deposition: The Next Frontier in Serum Lipidomics

Context: Strong evidence suggests that ectopic fat rather than fat mass per se drives risk for type 2 diabetes. Nonetheless, biomarkers of ectopic fat have gone unexplored. Objective: To determine the utility of serum lipidomics to predict ectopic lipid deposition. Design: Cross-sectional. Setting: The Clinical Translational Research Center at the University of Colorado Anschutz Medical Campus. Participants: Endurance-trained athletes (n = 15, 41 ± 0.9 y old; body mass index 24 ± 0.6 kg/m2) and obese people with or without type 2 diabetes (n = 29, 42 ± 1.4 y old; body mass index 32 ± 2.5 kg/m2). Intervention: Blood sampling and skeletal muscle biopsy. Main Outcome Measures: Multivariable models determined the ability of serum lipids to predict intramuscular (im) lipid accumulation of triacylglycerol (TAG), diacylglycerol (DAG), and ceramide (liquid chromatography tandem mass spectroscopy). Results: Among people with obesity, serum ganglioside C22:0 and lactosylceramide C14:0 predicted muscle TAG (overall ...