Quantification of choline in serum and plasma using a clinical nuclear magnetic resonance analyzer

•Gut microbiome-related metabolites, like choline, are increasingly recognized as contributors to, as well as markers of, cardiometabolic and other chronic diseases.•Because of the increasing interest in the effects of the gut microbiome on health/wellness and/or disease, an assay to simultaneously measure circulating concentrations of the gut microbiome-related metabolites was developed, and the analytical characteristics of the choline assay is reported here.•The newly developed NMR-based assay exhibited good performance characteristics enabling high-throughput quantification of circulating choline for clinical use. Choline, a gut microbiome metabolite, is associated with cardiovascular risk and other chronic illnesses. The aim was to develop a high-throughput nuclear magnetic resonance (NMR)–based assay to measure choline on the Vantera® Clinical Analyzer. A non-negative deconvolution algorithm was developed to quantify choline. Assay performance was evaluated using CLSI guidelines. Deming regression analysis comparing choline concentrations by NMR and mass spectrometry (n = 28) exhibited a correlation coefficient of 0.998 (intercept = –9.216, slope = 1.057). The LOQ were determined to be 7.1 µmol/L in serum and 5.9 µmol/L in plasma. The coefficients of variation (%CV) for intra- and inter-assay precision ranged from 6.2 to 14.8% (serum) and 5.4–11.3% (plasma). Choline concentrations were lower in EDTA plasma by as much as 38% compared to serum, however, choline was less stable in serum compared to plasma. In a population of apparently healthy adults, the reference interval was