A method for measuring glycerol-blanked triglyceride concentrations by using gas chromatography-isotope dilution mass spectrometry.

Abstract

Serum triglyceride concentrations are measured as total glycerides content in many Western countries. In Japan, glycerol-blanked triglycerides (TG-GB) are measured to identify postprandial hypertriglyceridaemia and to minimize the influence of glycerol formulation on serum triglyceride values. However, TG-GB measurements have not been standardized. Therefore, we developed an efficient quantification system for total glycerides and free glycerol that allows the calculation of TG-GB concentrations. We measured total glycerides and free glycerol in human serum by using gas chromatography-isotope dilution mass spectrometry and compared its performance to the reference method of the US Centers for Disease Control and Prevention (CDC). Our practical method of total glycerides and free glycerol quantification achieved excellent precision for both within-run and among-run coefficients of variation (<1.5% and <2.7%, respectively), with an average recovery of 99.8% for free glycerol. However, we noted an average %bias of -0.26% for total glycerides and -3.15% for free glycerol between our TG-GB method and the CDC reference method. This practical method of total glycerides and free glycerol quantification enables traceability assessment of TG-GB measurements. Differences between the output values of TG-GB and the CDC reference method might result from the differences in free glycerol values.