Figure 1.

Study design of day 1, 2 and 3. On day 1 an oral glucose tolerance test (OGTT), as well as DEXA scan and exercise test was performed. On day 2, we did the intravenous glucose tolerance test, followed by a hyperinsulinemic euglycemic clamp. Energy expenditure was assessed in fasting condition and during the steady state period of the clamp. On day 3, we performed insulin pulsatility testing followed by a graded hyperglycaemic clamp with arginine bolus and finally GLP-1 bolus to stress the β-cell maximally (for details - see Materials and Method section).