Comparison between monocomponent human insulin U-40 and U-100 in CSII treatment of type 1 diabetics

A multicentric study has been carried out to compare the efficacy and the safety of monocomponent human insulins of different concentration (Novo Actrapid HM U-40 and U-100) in CSII-treated Type 1 diabetics. 15 males, all of whom had been diabetic for at least 2 yr, had been treated by CSII and were skillful in the self-monitoring of diabetes were selected for observation at 3 different clinical centres (Bologna, Chieti and Torino). After a 1-week period of insulin dose optimization, the patients were asked not to modify either basal or pre-prandial insulin infusion during the following 2 weeks in which they were treated alternately by U-40 or by U-100 insulin (7 days for each treatment in random sequence). Each day or at least every other day, patients recorded at home a 9-point blood glucose profile by means of glucose-sensitive strips and photometric reading (Reflocheck System-BOEHRINGER MANNHEIM, FRG). The patients used the microinfuser Miles Microjet Bolus 2 for the U-40 infusion and the same model with appropriate modifications for the U-100 infusion. On the last day of each study period, blood samples were drawn after the pre-breakfast insulin bolus. Paired Student's t-test analyses between blood glucose values obtained with different regimens did not show a significant difference in metabolic control. Similarly no difference could be observed in insulin absorption after an identical bolus of U-40 or U-100 insulin. In conclusion human U-100 insulin seems to be as effective and safe as U-40 and is recommended in order to reduce the size of microinfusers.