title: 13C- and 2H-labelled glucose compared for minimal model estimates of glucose metabolism in man.
abstract: In the present study, we have investigated the use of 1-[(13)C]glucose and GC/combustion/isotope-ratio MS as an alternative to 6,6-[(2)H(2)]glucose and GC/MS in the determination of parameters of glucose metabolism using the IVGTT (intravenous glucose tolerance test) interpreted by labelled (hot) minimal models. The study has been done in four populations, normoglycaemics (subdivided into lean and obese individuals), subjects with impaired glucose tolerance and those with diabetes mellitus. Although the use of carbon label may in some circumstances be compromised by substrate recycling, our hypothesis was that this would not be an issue under the condition of suppression of hepatic glucose production during the short timescale of an IVGTT. In all four groups, we found that the methodology employing the carbon label gave equivalent results to those obtained using the conventional deuterated material, but the sensitivity of the measurement technique in the new approach was sufficient to allow an approx. 15-fold reduction in the quantity of isotope administered. In addition to the clear cost advantages, this represents a significant scientific advance in that true tracer status is more nearly attained in these measurements with near-physiological tracee loads.
authors.affiliation: Medical Research Council Human Nutrition Research, Elsie Widdowson Laboratory, Peterhouse Park, Fulbourn Road, Cambridge CB1 9NL, U.K. les.bluck@mrc-hnr.cam.ac.uk
authors.forename: Leslie J C
authors.initials: LJ
authors.lastname: Bluck
authors.forename: Allan T
authors.initials: AT
authors.lastname: Clapperton
authors.forename: W Andy
authors.initials: WA
authors.lastname: Coward
mesh_terms: D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D002247:Carbon Isotopes; D003365:Costs and Cost Analysis; D003903:Deuterium; D003924:Diabetes Mellitus, Type 2 / Q000175:diagnosis* / Q000378:metabolism; D004334:Drug Administration Schedule; D008401:Gas Chromatography-Mass Spectrometry; D005947:Glucose; D005951:Glucose Tolerance Test / Q000191:economics / Q000379:methods*; D006801:Humans; D007553:Isotope Labeling; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011849:Radioactive Tracers; D012680:Sensitivity and Specificity
chemical_list: D001786:Blood Glucose; D002247:Carbon Isotopes; D011849:Radioactive Tracers; D003903:Deuterium; D005947:Glucose