GCG and type 2 diabetes mellitus: The main aim of this investigation was therefore to quantify the reduction in insulin clearance following an oral glucose tolerance test compared to an isoglycemic intravenous glucose infusion in participants with type 2 diabetes (treated with metformin, sitagliptin, metformin/sitagliptin combination, or placebo) and to explore the possible association between the reduction in insulin clearance and the rise in incretin hormones levels.