Evaluation of Pharmacokinetics and Pharmacodynamic Properties of Rapid-Acting Insulin Analogs

The aim of this study is to evaluate the variations in pharmacokinetic (as determined by serum free insulin concentrations) and pharmacodynamic (as determined by the glucose infusion rate required to maintain euglycemia during a euglycemic clamp) properties of the rapid acting insulin analogs when given as a bolus by subcutaneous insulin infusion pump as typically encountered in the care of children with type 1 diabetes. The specific factors we will investigate are the effects of puberty (pre- vs. pubertal), type of insulin analog (lispro or aspart insulin), site of catheter insertion (gluteal vs. abdominal), and age of catheter (fresh insertion vs. three-day duration) Our hypotheses are that the peak (Imax) and area under the curve (IAUC) serum free insulin concentration, and the peak glucose infusion rate required to maintain euglycemia (GIRmax) and area under the curve (GIRAUC) will vary based on these conditions, in children given the same weight-based dose. We will also evaluate the pharmacokinetic and pharmacodynamic properties of Aspart and Lispro insulin when used in a basal-bolus regimen with insulin Detemir or Glargine, new basal insulin analogs, given as separate injections and when combined in a single injection in adolescent patients with Type 1 DM. We hypothesize that the peak (IMAX) and area under the curve (IAUC) serum insulin concentrations, and the peak glucose infusion rate required to maintain euglycemia (GIRMAX) and area under the curve (GIRAUC) of the Aspart/Lispro bolus, will be similar when the Aspart/Lispro is combined in the same syringe with the insulin Detemir/Glargine, compared to when the Aspart/Lispro and Detemir/Glargine are given as two separate injections.