Abstract 13393: Liraglutide Improves Myocardial Redox State in Humans by Regulating the Adipose Tissue-Derived Long-Chain Ceramides
Introduction: A notable reduction in major adverse cardiovascular events and cardiovascular mortality was observed in several cardiovascular studies via treatment with liraglutide, which have been suggested to be mediated through several mechanisms including inhibition of oxidative stress. Hypothesis: We hypothesised that treatment with liraglutide reduces oxidative stress via modulating circulating levels of long-chain ceramides. Methods: We measured vascular superoxide production using lucigenin-enhanced chemiluminescence and levels of circulating ceramides using LC-MS/MS in 633 participants of the Oxford Heart Vessels and Fat (OxHVF) cohort. We also measured 33 sphingolipid species (SPL) in plasma from 32 obese individuals (average BMI 33.5±2.5kg/m 2 at inclusion) participating in a randomized clinical trial (RCT) of low calorie diet and liraglutide. Results: We found a significant association between superoxide production by internal mammary arteries (IMA) and circulating levels of long-chain ceramides (C16:0, C17:0, C18:0, C18:1) (A-D) . In the RCT, all participants adhered to an 8-week low-calorie diet (800 kcal/day) (E) , during which they lost 9.9±6.0 kg of body weight exhibiting a significant reduction in BMI ( p <0.0001), which was paralleled by significant effects on the circulating levels of SPL (F) . Following this initial phase, the patients were randomised to liraglutide treatment (1.2 mg daily) or no treatment, for a period of 52 weeks. Liraglutide treatment differentially affected several SPL species compared to the control group despite no significant changes in BMI in any of the two groups (G-J) . Conclusions: In this study, we observed for the first time in human a regulatory effect of liraglutide on the circulating levels of long-chain ceramides that are shown to be associated with vascular oxidative stress suggesting a promising mechanistic link that justifies further exploration.