[Action profile of human ultralente insulin compared with human NPH-insulin]

The effect of human NPH insulin (Protaphan HM) and of human ultralente insulin (Ultratard HM) on the profile of blood-glucose concentration was compared, using the glucose clamp technique, in normal subjects after subcutaneous injection of 12 U each. After Protaphan, insulin concentration rose by 11.0 +/- 1.6 microU/ml; maximal glucose infusion rate (GIR) after five hours was 4.7 +/- 0.5 mg/kg.min. But after the same dosage of Ultratard, insulin concentration rose by only 4.7 +/- 1.0 microU/ml (P less than 0.02) on a maximal GIR after ten hours of 3.2 +/- 0.5 mg/kg.min (no significant difference). Ultratard had up to 70% of the maximal Protaphan effect, the infused amount of glucose, up to maximal effect at 9.5 h (72 +/- 9 g), being significantly lower (P less than 0.02) than after Protaphan (130 +/- 18 g). After, respectively, 16 (Protaphan) and 20 (Ultratard) hours, basal insulin levels were again reached. GIR 19 h after Protaphan injection was 1.3 +/- 0.4 mg/kg.min, while 24 h after Ultratard it was 1.5 +/- 0.2 mg/kg.min, which was not significantly different from the basal rate. The difference between Protaphan and Ultratard lies in the marked initial effect of NPH insulin, up to 10 h after injection. In the later phase of the effect profile both insulins were similar at the chosen dose of 12 U.