Relationship between Systemic Biomarker of Lipid Peroxidation 4-Hydroxynonenal and Lipidomic Profile of Morbidly Obese Patients undergoing Bariatric Surgery

Obesity is characterized by fat accumulation, impaired metabolism and oxidative stress, frequently associated with lipid peroxidation and generation of bioactive 4-hydroxynonenal (4-HNE). This study aimed to evaluate the impact of bariatric surgery-induced weight loss on lipid peroxidation and associated perturbations in lipid profile. Plasma samples of twenty obese individuals before and 6 months after bariatric surgery were collected in addition to samples of ten healthy controls. HILIC-LC-MS/MS platform was used to characterize phospholipid profile, while lipid peroxidation markers 15-F2t-IsoP, 10-F4t-IsoP and reactive aldehyde 4-HNE were quantified by RP-LC-MS/MS and GC-MS, respectively. Six months post-surgery lipid peroxidation markers decreased significantly and the BMI of morbidly obese patients decreased by 13 on average. Lipidomics analysis, identified 117 phospholipid species from seven classes, and showed obesity-associated lipidome perturbations, particularly in ether-linked phosphatidylethanolamines (PEo). A total of 45 lipid species were found to be significantly altered with obesity, while 10 lipid species correlated with lipid peroxidation markers. Sample pairwise analyses indicated an interesting link between 4-HNE and the amount of two ether-linked phosphatidylethanolamines PEo(38:2) and PEo(36:2). The results indicate that weight loss-induced improvement of redox homeostasis together with changes in lipid metabolites may serve as markers of metabolic improvement. However, further studies are needed to understand the role of obesity-induced oxidative stress on ether lipid biosynthesis and lipidome perturbations, as well as the impact of bariatric surgery on metabolic improvement.