Figure 1
Protocol of the euglycemic and hyperglycemic clamp performed before and three weeks after each intervention. The euglycemic clamp (upper panel) involves a continuous insulin infusion (0.28 nmol/m2/min), adjusted via variable 20% glucose infusion to maintain a blood glucose level of 120 mg/dL based on 5-min interval bedside glucose measurements. Blood samples were taken at − 15, 90, 105, and 120 min to assess insulin and glucose. The hyperglycemic clamp (lower panel) raises blood glucose to 180 mg/dL using graded glucose infusions between T0 and T170 with blood samples at − 30, − 15, 0 to measure baseline glucose, insulin, and C-peptide before glucose infusion is started. Consequently, blood samples were collected at 5, 10, 120, 135, 150, 155, and 160 min to measure glucose, insulin, and C-peptide to evaluate first, second, and third phase beta-cell responses, respectively. Glucagon (1 mg) was injected at 150 min to assess maximal secretory capacity.
