TABLE 1

Comparison of glucose and glycogen measurements before clamps in the utilization study (means ± SD between subjects)

Euglycemia studyHypoglycemia studyP (paired t test)
[Mean plasma glucose] during overnight infusion (mg/dl)129 ± 13129 ± 220.97
Mean isotopic enrichment of plasma glucose during overnight infusion (%)83 ± 978 ± 110.22
[13C-glycogen] at baseline (μmol/g)1.2 ± 0.21.3 ± 0.20.86
[Newly synthesized glycogen] at baseline (μmol/g)*1.4 ± 0.31.5 ± 0.20.36
[13C-glycogen] at the beginning of clamp (μmol/g)1.4 ± 0.11.2 ± 0.30.12
[Newly synthesized glycogen] at the beginning of clamp (μmol/g)1.7 ± 0.31.5 ± 0.20.24
  • *Newly synthesized: corrected for plasma glucose isotopic enrichment during infusions.

  • †These are the glycogen levels obtained in the first 30 min of the 2-h clamps.