The absorption kinetics of subcutaneously infused U 40 and U 100 insulin in diabetics.

The influence of U 40 and U 100 insulin on the insulin kinetics during continuous subcutaneous insulin infusion (CSII) was investigated in eight insulin-dependent diabetics. CSII was started at t = -1.5 h with a bolus of 2 IU at the individual treatment infusion rate (22-35 IU/24 h), followed at t = 0 h by a premeal dose of 6 IU. Insulin delivery was interrupted for 120 min at t = 4 h and reinitiated with a loading dose of 2 IU for another 2 h. The incremental peak plasma free insulin levels and the time to reach these levels after the premeal insulin dose were not significantly different: 17 +/- 2 vs. 16 +/- 2 mU/l and 144 +/- 22 vs. 129 +/- 9 min for U 40 and U 100 insulin, respectively. During the 2 h interruption of insulin delivery plasma free insulin levels declined by 5.0 +/- 1.6 and 7.2 +/- 1.3 mU/l (NS) for U 40 and U 100 insulin, respectively. The blood glucose profiles were virtually identical throughout the studies for either insulin concentration. These results indicate that varying the insulin concentration in the range between U 40 and U 100 does not affect the insulin kinetics during CSII in insulin-dependent diabetics.