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Quantification of gluconeogenesis in a single blood sample by 2H nuclear magnetic resonance spectroscopy
Track 4. Basic Research
min (0.3g glucose/kg with lOmg/kg U13CG and 16mg/kg 30MG). In total, 52 samples were taken every l-30 min over 360 min to determine plasma glucose, insulin, U13CG, and 30MG concentrations. A two compartment model of glucose kinetics was postulated with a separate remote effect of insulin on GT (determined by 30MG and U13CG kinetics) and GD (determined by U13CG kinetics). SIT and Sm were obtained from model parameters which were estimated by simultaneously fitting U13CG and 30MG curves over O-360min. The model fitted the data well as judged by the distribution and extent of weighted residuals. SIT was significantly higher than S’n (39 (22-66) vs 5 (2-13)x10-4/min per mU& mean (95% CI); p=O.O3). The two sensitivity indices were not correlated (r&.49; p=O.33). During IVG’IT, insulin activated GT more slowly than GD. In addition, halftime of GT deactivation was longer than that of GD (166 (88-313) vs 9 (4-19)min; pcO.03). This resulted in a maximum GT above-basal increase by 60% (30-96) compared to 336% (156-744) of GD. We conclude that the dynamics and extent of insulin action on GT and GD differ with immediate and several fold increase of GD and slower but prolonged increase of GT during IVGTT.
P647 Quantilication of Gluconeogenesis in a Single Blood Sample by *H Nuclear Magnetic Resonance Spectroscopy H. STINGL’, M. KrSSak’, E. Rosian2, 0. Kunert’, K. Zangger’, D. Weghuber’, P. Nowotny ‘, W. Waldhausl ‘, E. Haslinger’, M. Roden’. ’ Dept. Int. Med. 3, Univ. Vienna. Austria; 2 Dept. Pharmaceut. Chem., Univ. Graz, Austria
Recently developed techniques for the determination of gluconeogenesis (GNG) like the deuterated water (2HaO) method and 13C nuclear magnetic resonance spectroscopy (NMRS) improved the accuracy of measurements, but require either extensive chemical procedures or are not generally available. Here we use in vitro ‘H NMRS to determine ‘H enrichments in all carbons of blood glucose and to directly quantify fractional GNG in one blood sample. Following a mixed meal healthy volunteers (n=7) fasted for 17 h. After 2Hz0 ingestion (5 g/kg body HzO) blood was drawn at 13 h, 15 h and 17 h. Blood glucose was purified by ion-exchange chromatography and anomeric purity was achieved by acetylation. ‘H enrichments were analyzed with unlocked 2H NMRS (Varian Unity INOVA 400) and least squares fitting of the resonances to determine GNG from 2H in C5/C2. Using the C5/C2 ratio, GNG increased (~~0.05) from 13 h to 15 h and 17 h (53&8,64&4,76&6%) giving a mean GNG of 70f5%. To compare the results with a standard method, subjects were m-examined using in vivo 13C NMRS combined with D-[6,6-‘HIglucose infusion. In this case, GNG was determined from the difference of endogenous glucose production (EGP) and net hepatic glycogenolysis. EGP declined from 12.6f0.4 to 11.2f0.4 pmol.kg-‘.min-’ (~‘0.05). Net hepatic glycogenolysis was 3.8f0.6 pmol.kg-‘.min so that mean GNG measured was 67f5%. Estimates of GNG obtained by both methods exhibited a clear linear correlation (1=0.8, p=O.O2). In conclusion, the results show that in vitro *H NMRS offers a new and valid approach to directly quantify gluconeogenesis in a single blood sample. This should improve clinical investigation on metabolic defects and therapeutic drug effects.
P648 Heterogeneity of Glucose Metabolism at Rest and during Exercise in Obesity as Measured Using [‘*F]-FDG and PET KIRSTI LARMOLA ‘s3, Pauliina Peltoniemi ‘s3,Jukka Kemppainen ‘v3, Hanna Lame ‘s3, Kari Kalliokoski 3, Hannele Yki-J&vine”*, Juhani Knuuti3, Pirjo Nuutila’,3. ‘Dept.of Medicine, University of Turku, Turku; ‘Dept. of Medicine, University of Helsinki, Helsinki: ’ Turku PET Centre, Turku, Finland
We determined whether glucose uptake (GU) is heterogeneous in human skeletal muscle, and whether such heterogeneity is influenced by obesity.
S163
The effect of insulin and isometric exercise on heterogeneity of GU (measured as coefficient of variation (SD/mean) of GU) in anterolateral muscle compartment of thigh was compared in 7 obese (BMI 36f6 kg/m2) and 7 non-obese age-matched subjects (BMI 23f2 kg/m*) during euglycemic hyperinsulinemia (serum insulin -70 mu/L) and one-legged exercise. Furthermore, we studied an association between muscle GU and heterogeneity of GU. Oxygen consumption and GU were measured simultaneously in both femoral regions using [‘so]-02, [“F]-FDG and positron emission tomography (PET). Muscle oxygen consumption was -15-fold higher in the exercising muscle compared to the resting contralateral muscle and similar in both groups during exercise (30 mL/kg muscle.min). The obese subjects exhibited resistance both to insulin stimulation of GU (22f4 vs. 61f8 hmol/kg muscle.min, p~O.01, for obese vs. non-obese) and to exercise stimulated GU (9Of15 vs. 149f22 ymol/kg muscle.min, p
P649 Insulin and Exercise Stimulated Glucose Uptake and Its Heterogeneity in Subjects with Type 1 Diabetes. In Vivo Studies Using [“O]-HzO, [150]-02, [‘*F]-FDG and PET PAULIINA PELTONIEMI ‘By,Hannele Yki-Jarvinen’, Vesa Oikonen’, Tapani Ronnemaa3, Juhani Knuuti ‘, Pirjo Nuutila ‘s3. ’ Turku PET Centre, Turku, Finland; 2 Department of Medicine, University of Helsinki, Helsinki, Finland; 3 Department of Medicine, University of Turku, Turku, Finland
Insulin and exercise increase glucose uptake in part via distinct mechanisms, but it is unknown whether glucose uptake is resistant to other stimuli than insulin in subjects with type 1 diabetes in vivo. We compared the ability of insulin and exercise to stimulate muscle blood flow and glucose uptake in 11 subjects with type 1 diabetes, (BMI 23f0.4 kg/m*) and 10 age and weight matched healthy subjects during euglycemic hyperinsulinemia (serum insulin -70 mu/L) and regional one-legged exercise (anterolateral muscle compartment). Muscle blood flow, oxygen consumption and glucose uptake were measured simultaneously in both femoral regions using [‘50]-labelled water, [“O]-02, [“F]-FDG and positron emission tomography (PET). Heterogeneity of glucose uptake was determined as the coefficient of variation (SD/mean within an anterolateral muscle region). Exercise increased muscle oxygen consumption -1 l-fold in both groups (to 25 mL/kg muscle.min, NS between groups). Muscle blood flow was similar in both groups at rest and was increased by exercise -5-fold (NS between groups). The subjects with diabetes exhibited resistance both to insulin stimulation of glucose uptake in resting muscles (4847 vs 81f13 pmol/kg muscle.min, ~~0.05) and to exercise stimulated glucose uptake (167f25 vs 273f37 pmol/kg muscle.min, p
min (0.3g glucose/kg with lOmg/kg U13CG and 16mg/kg 30MG). In total, 52 samples were taken every l-30 min over 360 min to determine plasma glucose, insulin, U13CG, and 30MG concentrations. A two compartment model of glucose kinetics was postulated with a separate remote effect of insulin on GT (determined by 30MG and U13CG kinetics) and GD (determined by U13CG kinetics). SIT and Sm were obtained from model parameters which were estimated by simultaneously fitting U13CG and 30MG curves over O-360min. The model fitted the data well as judged by the distribution and extent of weighted residuals. SIT was significantly higher than S’n (39 (22-66) vs 5 (2-13)x10-4/min per mU& mean (95% CI); p=O.O3). The two sensitivity indices were not correlated (r&.49; p=O.33). During IVG’IT, insulin activated GT more slowly than GD. In addition, halftime of GT deactivation was longer than that of GD (166 (88-313) vs 9 (4-19)min; pcO.03). This resulted in a maximum GT above-basal increase by 60% (30-96) compared to 336% (156-744) of GD. We conclude that the dynamics and extent of insulin action on GT and GD differ with immediate and several fold increase of GD and slower but prolonged increase of GT during IVGTT.
P647 Quantilication of Gluconeogenesis in a Single Blood Sample by *H Nuclear Magnetic Resonance Spectroscopy H. STINGL’, M. KrSSak’, E. Rosian2, 0. Kunert’, K. Zangger’, D. Weghuber’, P. Nowotny ‘, W. Waldhausl ‘, E. Haslinger’, M. Roden’. ’ Dept. Int. Med. 3, Univ. Vienna. Austria; 2 Dept. Pharmaceut. Chem., Univ. Graz, Austria
Recently developed techniques for the determination of gluconeogenesis (GNG) like the deuterated water (2HaO) method and 13C nuclear magnetic resonance spectroscopy (NMRS) improved the accuracy of measurements, but require either extensive chemical procedures or are not generally available. Here we use in vitro ‘H NMRS to determine ‘H enrichments in all carbons of blood glucose and to directly quantify fractional GNG in one blood sample. Following a mixed meal healthy volunteers (n=7) fasted for 17 h. After 2Hz0 ingestion (5 g/kg body HzO) blood was drawn at 13 h, 15 h and 17 h. Blood glucose was purified by ion-exchange chromatography and anomeric purity was achieved by acetylation. ‘H enrichments were analyzed with unlocked 2H NMRS (Varian Unity INOVA 400) and least squares fitting of the resonances to determine GNG from 2H in C5/C2. Using the C5/C2 ratio, GNG increased (~~0.05) from 13 h to 15 h and 17 h (53&8,64&4,76&6%) giving a mean GNG of 70f5%. To compare the results with a standard method, subjects were m-examined using in vivo 13C NMRS combined with D-[6,6-‘HIglucose infusion. In this case, GNG was determined from the difference of endogenous glucose production (EGP) and net hepatic glycogenolysis. EGP declined from 12.6f0.4 to 11.2f0.4 pmol.kg-‘.min-’ (~‘0.05). Net hepatic glycogenolysis was 3.8f0.6 pmol.kg-‘.min so that mean GNG measured was 67f5%. Estimates of GNG obtained by both methods exhibited a clear linear correlation (1=0.8, p=O.O2). In conclusion, the results show that in vitro *H NMRS offers a new and valid approach to directly quantify gluconeogenesis in a single blood sample. This should improve clinical investigation on metabolic defects and therapeutic drug effects.
P648 Heterogeneity of Glucose Metabolism at Rest and during Exercise in Obesity as Measured Using [‘*F]-FDG and PET KIRSTI LARMOLA ‘s3, Pauliina Peltoniemi ‘s3,Jukka Kemppainen ‘v3, Hanna Lame ‘s3, Kari Kalliokoski 3, Hannele Yki-J&vine”*, Juhani Knuuti3, Pirjo Nuutila’,3. ‘Dept.of Medicine, University of Turku, Turku; ‘Dept. of Medicine, University of Helsinki, Helsinki: ’ Turku PET Centre, Turku, Finland
We determined whether glucose uptake (GU) is heterogeneous in human skeletal muscle, and whether such heterogeneity is influenced by obesity.
S163
The effect of insulin and isometric exercise on heterogeneity of GU (measured as coefficient of variation (SD/mean) of GU) in anterolateral muscle compartment of thigh was compared in 7 obese (BMI 36f6 kg/m2) and 7 non-obese age-matched subjects (BMI 23f2 kg/m*) during euglycemic hyperinsulinemia (serum insulin -70 mu/L) and one-legged exercise. Furthermore, we studied an association between muscle GU and heterogeneity of GU. Oxygen consumption and GU were measured simultaneously in both femoral regions using [‘so]-02, [“F]-FDG and positron emission tomography (PET). Muscle oxygen consumption was -15-fold higher in the exercising muscle compared to the resting contralateral muscle and similar in both groups during exercise (30 mL/kg muscle.min). The obese subjects exhibited resistance both to insulin stimulation of GU (22f4 vs. 61f8 hmol/kg muscle.min, p~O.01, for obese vs. non-obese) and to exercise stimulated GU (9Of15 vs. 149f22 ymol/kg muscle.min, p
P649 Insulin and Exercise Stimulated Glucose Uptake and Its Heterogeneity in Subjects with Type 1 Diabetes. In Vivo Studies Using [“O]-HzO, [150]-02, [‘*F]-FDG and PET PAULIINA PELTONIEMI ‘By,Hannele Yki-Jarvinen’, Vesa Oikonen’, Tapani Ronnemaa3, Juhani Knuuti ‘, Pirjo Nuutila ‘s3. ’ Turku PET Centre, Turku, Finland; 2 Department of Medicine, University of Helsinki, Helsinki, Finland; 3 Department of Medicine, University of Turku, Turku, Finland
Insulin and exercise increase glucose uptake in part via distinct mechanisms, but it is unknown whether glucose uptake is resistant to other stimuli than insulin in subjects with type 1 diabetes in vivo. We compared the ability of insulin and exercise to stimulate muscle blood flow and glucose uptake in 11 subjects with type 1 diabetes, (BMI 23f0.4 kg/m*) and 10 age and weight matched healthy subjects during euglycemic hyperinsulinemia (serum insulin -70 mu/L) and regional one-legged exercise (anterolateral muscle compartment). Muscle blood flow, oxygen consumption and glucose uptake were measured simultaneously in both femoral regions using [‘50]-labelled water, [“O]-02, [“F]-FDG and positron emission tomography (PET). Heterogeneity of glucose uptake was determined as the coefficient of variation (SD/mean within an anterolateral muscle region). Exercise increased muscle oxygen consumption -1 l-fold in both groups (to 25 mL/kg muscle.min, NS between groups). Muscle blood flow was similar in both groups at rest and was increased by exercise -5-fold (NS between groups). The subjects with diabetes exhibited resistance both to insulin stimulation of glucose uptake in resting muscles (4847 vs 81f13 pmol/kg muscle.min, ~~0.05) and to exercise stimulated glucose uptake (167f25 vs 273f37 pmol/kg muscle.min, p