Plasma Lipidome Analysis by Liquid Chromatography-High Resolution Mass Spectrometry and Ion Mobility of Hypertriglyceridemic Patients on Extended-Release Nicotinic Acid: a Pilot Study.

BACKGROUND: Plasma high triacylglycerols and low HDL-C concentration are associated with increased cardiovascular events. Extended-release nicotinic acid (ERN) was shown to reduce plasma triacylglycerols and total cholesterol but also to markedly increase high-density lipoprotein-cholesterol (HDL-C). No data on the effect of ERN on different species of triacylglycerol, cholesteryl ester, and phospholipids are available. In this study, we applied a nontargeted lipidomic approach to investigate the plasma and lipoproteins lipids profile of hypertriglyceridemic patients treated with ERN or a placebo in order to identify new lipids markers associated with this treatment.

METHODS: Eight hypertriglyceridemic patients enrolled in a crossover randomized trial with ERN for 8 weeks and treated with 2 g/day of ERN or a placebo. Ultra-performance liquid chromatography (UPLC) coupled to high-resolution mass spectrometry (HRMS) was used in mass spectrometry energy mode (HRMSE ) combined with ion mobility spectrometry to characterize the plasma and very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL) lipidome. The accuracy and precision of the method were validated on plasma samples.

RESULTS: Compared to placebo, among 155 plasma lipids characterized using UPLC-ESI-HRMS, a multivariate analysis revealed a significant increase of lysophosphatidylcholine (LPC 20:5), a significant decrease of phosphatidylethanolamine (PE 16:0/22:3) and sphingomyelin (SM d18:1/22:0) and a decrease of triacylglycerol (TG 16:0/16:1/18:2) after ERN treatment. Analysis of these lipids in lipoproteins showed an increase of LPC (20:5) in HDL, a decrease of PE (16:0/22:3) in HDL and LDL, of SM (d18:1/22:0) in VLDL and LDL and of TG (16:0/16:1/18:2) in VLDL.

CONCLUSION: This lipidomic strategy characterized new specific lipid markers likely to be involved in the effect of ERN on cardiovascular risk opening a new strategy to analyze randomized controlled with this treatment.

TRIAL REGISTRATION: NCT01216956.