To study the pharmacokinetics and pharmacodynamics of three different modes of
insulin infusion delivered by means of an
insulin pump: subcutaneous bolus
insulin injection once an hour, continuous subcutaneous
insulin infusion and continuous intravenous
insulin infusion.
METHODS: RESULTS: A non-random, sinus-like variation of serum
insulin aspart over time was found with subcutaneous bolus
insulin injection compared with continuous subcutaneous
insulin infusion and continuous intravenous
insulin infusion (P<0.0001). Random variation of serum
insulin aspart over time was significantly higher with continuous intravenous
insulin infusion compared with subcutaneous bolus
insulin injection (P=0.023) and continuous subcutaneous
insulin infusion (P=0.013). Mean serum
insulin aspart did not differ significantly between subcutaneous bolus
insulin injection, continuous subcutaneous
insulin infusion and continuous intravenous
insulin infusion (P=0.17). Thus, absolute bioavailability was near 100% for both subcutaneous bolus
insulin injection and continuous subcutaneous
insulin infusion. Statistically significant differences were seen in mean plasma
glucose and mean
glucose infusion rate, with the highest mean plasma
glucose and the lowest mean
glucose infusion rate with continuous intravenous
insulin infusion, suggesting a slightly lower bioefficacy of continuous intravenous
insulin infusion compared with subcutaneous bolus
insulin injection and continuous subcutaneous
insulin infusion.
CONCLUSIONS: Small but statistically significant differences in pharmacokinetics and pharmacodynamics between subcutaneous bolus
insulin injection, continuous subcutaneous
insulin infusion and continuous intravenous
insulin infusion were observed. However, no major clinically relevant differences were found, suggesting that, for a basal subcutaneous
insulin aspart pump
therapy, relatively infrequent pump
stroke frequency may suffice.