Assessment of Liver Glucose Metabolism in Diabetic Subjects

The hyperinsulinemic euglycemic clamp represents the gold standard for measuring peripheral insulin sensitivity. The insulin sensitivity is described by the M-value,which is calculated from glucose infusion rates during the last 30min of the clamp.

Glucose is metabolised in the periphery: 50% by neural tissues, 20% by splanchnic bed and liver, 15% by skeletal muscle, 5% by adipose tissue and 10% by blood cells and other tissues. Under hyperinsulinemic conditions there is a strong shift in glucose utilization: 85% skeletal muscle and 15% by neural tissues, splanchnic bed and liver, adipose tissue, blood cells and other tissues. The contribution of skeletal muscle varies with different insulin sensitivity.

We now want to investigate whether there is a difference in tissue-specific insulin sensitivity measured from a Botnia clamp (intravenous glucose tolerance test (ivGTT) and following clamp) and a single hyperinsulinemic euglycemic clamp? After a 60min ivGTT blood glucose levels in type 2 diabetic subjects are still elevated compared to baseline. High blood glucose levels can influence several parameters and may also affect insulin sensitivity. Until now, it is not proven, that the clamp preceding ivGTT does not have a significant influence on the M-value.