Obesity is Associated with Changes in Plasma Oxylipids

Abstract

Oxylipids, oxygenated fatty acids, are implicated in inflammation, immune cell signaling, and tumor survival. The link between obesity, inflammation, and cancer is well‐accepted, but it is unknown if obesity is associated with specific oxylipids. The objective of this study was to identify associations between non‐esterified plasma oxylipids and body mass index (BMI). 126 Caucasian males (48‐65 years) were categorized: lean (BMI<25), overweight (25£BMI<30) or obese (BMI³30). Plasma non‐esterified oxylipids were analyzed using solid phase extraction and quantified using a HPLC tandem mass spectrometric analysis. Obese individuals were 1.2 (p<0.05) times more likely to have elevated plasma arachidonate derived 8,9‐epoxy eicosatrienoate (8,9‐EET) compared to lean individuals. Plasma auto‐oxidative arachidonate products, 9‐hydroxy eicosatetraenoic acid (9‐HETE) (P<0.01) and 11‐HETE (p<0.005), were elevated in obese men. Also, lipoxygenase products 15‐HETE (<0.005), 15‐keto ETE (p<0.01), and cytochrome p450 product 20‐HETE (p<0.05) were increased in obese men compared to lean. 16, 17‐epoxy docosapentaenoate was 0.6 (p<0.01) and 0.7 (p<0.05) times less abundant in plasma from overweight and obese men respectively, compared to that of lean. Overall arachidonate enzymatic and non‐enzymatic oxygenation is increased in obesity, including “proinflammatory‐like” oxylipids. Future studies should examine the role of these oxylipids in the initiation of obesity‐associated diseases such as cancer. Research Support: NIH R03CA142000 and MSU CTSI