Clamp protocol A combined hyperinsulinemic-euglycemic and hyperglycemic clamp will be performed. During the euglycemic clamp insulin will be infused at 40 microunits/square meter.minute (mU/m2.min) and glucose will be kept at 5 mmol/l by variable glucose 20% infusion. This technique allows for renal measurements during normoglycemia in all participants. After 3 hours of insulin infusion and an one hour rest period for exogenous insulin to be cleared, glucose will be infused in order to reach a plasma concentration of 15 mmol/l. In this matter, renal tests can be performed under stable hyperglycemia. From the euglycemic clamp, insulin sensitivity will be determined from the amount of glucose infused (M-value). Blood will be stored during hyperglycemia in order to be able to obtain measures of beta-cell function, including 1st phase insulin secretion, 2nd phase insulin secretion and arginine-induced insulin secretion.