A single-run, rapid polarity switching method for simultaneous quantification of cardiovascular disease-related metabolites using liquid chromatography–tandem mass spectrometry

Abstract Several amino acids, nucleotide metabolites, organic acids, and choline-related metabolites have been identified as possible risk factors for cardiovascular disease (CVD). However, a method that allows rapid processing of a large number of samples while simultaneously quantifying metabolite concentrations is currently unavailable. Here, we developed a simple and reliable method for quantifying metabolomic risk factors of CVD using liquid chromatography–tandem mass spectrometry (LC–MS/MS), and assessed its efficacy using serum samples from patients with angiographically defined coronary artery disease (CAD). Serum samples were mixed with isotopically labeled internal standards, extracted with methanol, and separated by hydrophilic interaction LC. MS detection was simultaneously performed in both positive and negative ionization modes coupled with real-time polarity switching, resulting in markedly improved monitoring capacity and reduced overall run time. In total, 20 metabolites were analyzed in 4 min. The mean linear correlation coefficients were higher than 0.999, with average analytical recoveries of 101.9% (range: 90.1–110.9%). The intra-run and total coefficients of variation (CV) were 1.02-6.11% and 1.25-9.41%, respectively. Several metabolites were significantly associated with traditional CVD risk factors. Multivariable logistic regression analysis revealed that tryptophan and hypoxanthine were negatively correlated with CAD, while trimethylamine-N-oxide was positively correlated with CAD. The method developed in this study is simple, precise, accurate, and provides a potentially convenient tool for CVD risk assessment and future research.