 Blood samples will be collected at time points: -65, -60, -30, 0, 3, 4, 5, 6, 8, 10, 14, 19, 22, 27, 30, 35, 40, 50, 60, 70, 90, 100, 120, 140, 150 and 180 min for the measurement of glucose, insulin and C-peptide 8 ml per time point: time points -30, 0, 3, 4, 5, 6, 8, 10, 14, 19, 22, 27, 30, 35, 40, 50, 70, 100, 140 and 180 min, for the measurement of BNP and NT-proBNP 4 ml per time point: time points -65, -60, -30, 0, 30, 60, 90, 120, 150 and 180 min and for the measurement of plasma sodium, potassium and creatinine 8 ml per time point: time points -60, 60 and 180 minutes. 