BACKGROUND: Obesity is often accompanied by a decreased ability of insulin to stimulate glucose uptake and glycogenesis in skeletal muscle. The aim of this study was to investigate the rate of glycogen formation and of muscular glucose content in relation to insulin sensitivity under euglycemic conditions. MATERIALS AND METHODS: We applied a hyperinsulinemic (430 pmol m-2 min-1) euglycemic clamp with infusion of 20% glucose (30% enriched with 13C-1-glucose) to 8 subjects with a wide range of insulin sensitivities. Glycogen and glucose levels were monitored simultaneously by in vivo 13C MRS of the calf muscle on a clinical MR system at 1.5T field strength. RESULTS AND CONCLUSIONS: Glycogen synthesis rate showed a strong correlation with whole body glucose uptake during the clamp (r = 0.93, P < 0.01). With the use of 13C MRS, total muscular glucose content could be determined in vivo, and showed a positive, linear correlation with glycogen synthesis rate (r = 0.85, P < 0.01). 13C MRS provides important information regarding in vivo insulin action. Preliminary results indicate that the glycogen synthesis rate improves after treatment with troglitazone.
BACKGROUND: Obesity is often accompanied by a decreased ability of insulin to stimulate glucose uptake and glycogenesis in skeletal muscle. The aim of this study was to investigate the rate of glycogen formation and of muscular glucose content in relation to insulin sensitivity under euglycemic conditions. MATERIALS AND METHODS: We applied a hyperinsulinemic (430 pmol m-2 min-1) euglycemic clamp with infusion of 20% glucose (30% enriched with 13C-1-glucose) to 8 subjects with a wide range of insulin sensitivities. Glycogen and glucose levels were monitored simultaneously by in vivo 13CMRS of the calf muscle on a clinical MR system at 1.5T field strength. RESULTS AND CONCLUSIONS:Glycogen synthesis rate showed a strong correlation with whole body glucose uptake during the clamp (r = 0.93, P < 0.01). With the use of 13CMRS, total muscular glucose content could be determined in vivo, and showed a positive, linear correlation with glycogen synthesis rate (r = 0.85, P < 0.01). 13CMRS provides important information regarding in vivo insulin action. Preliminary results indicate that the glycogen synthesis rate improves after treatment with troglitazone.
Authors: Kim C C van de Ven; Cees J Tack; Arend Heerschap; Marinette van der Graaf; Bastiaan E de Galan Journal: J Clin Invest Date: 2013-01-09 Impact factor: 14.808
Authors: Kim C C van de Ven; Marinette van der Graaf; Cees J Tack; Arend Heerschap; Bastiaan E de Galan Journal: Diabetes Date: 2012-06-11 Impact factor: 9.461
Authors: Marinette van der Graaf; Jacco H de Haan; Paul Smits; Alexandra H Mulder; Arend Heerschap; Cees J Tack Journal: Eur J Appl Physiol Date: 2010-09-24 Impact factor: 3.078
Authors: Kim C C van de Ven; Bastiaan E de Galan; Marinette van der Graaf; Alexander A Shestov; Pierre-Gilles Henry; Cees J J Tack; Arend Heerschap Journal: Diabetes Date: 2011-04-04 Impact factor: 9.461