A Convenient LC-MS Method for Assessment of Glucose Kinetics In Vivo with D-[13C6]Glucose as a Tracer

tolerance test (IVGTT) combined with computer modeling is widely used to derive parameters related to glucose metabolism in vivo. Most of these methods in-volve use of either 2H2-labeled or 13C1-labeled D-glu-cose as a tracer with GC-MS to measure the isotope enrichment. Thesemethods are challenging, both tech-nologically and economically. We have developed a novel approach that is suitable for labeled-IVGTT studies involving a large cohort of individuals. METHODS: The tracer, D-[13C6]glucose, is a low-cost al-ternative with the significant advantage that the sixth isotope of natural glucose has virtually zero natural abundance, which facilitates isotopomer analysis with 1 % labeled glucose in the infusate. After deprotein