Comparative study of hormonal counter-regulation during GCIIS-guided insulin hypoglycemia tests using human insulin (recombinant DNA) and pork insulin

Abstract

Human insulin (BHI, recombinant DNA) and pork insulin (PI) were compared in 10 healthy volunteers. Using a glucose controlled insulin infusion system for the performance of the insulin hypoglycemia test (IHT), a comparable dosage of both insulins had to be infused (BHI 0.129 +/- 0.007 vs PI 0.115 +/- 0.01 U/kg; mean +/- SEM). Blood glucose slopes and nadirs did not differ significantly (BHI 30 +/- 2 vs PI 29 +/- 2 mg/dl). There was no difference in C-peptide inhibition (minimum for BHI 0.50 +/- 0.08 vs PI 0.42 +/- 0.08 micrograms/l). Maximum hormone responses were identical for ACTH (BHI 78.4 +/- 11.3 vs PI 76.0 +/- 8.7 pg/ml), cortisol (BHI 246 +/- 20 vs PI 252 +/- 15 ng/ml) and GH (BHI 43.8 +/- 7.3 vs PI 49.4 +/- 6.7 ng/ml). Peak levels of prolactin did not differ significantly (BHI 1,335 +/- 315 vs PI 1,766 +/- 614 microU/ml). The urinary excretion pattern of epinephrine in three 120 min periods before, during and after IHT was identical (before IHT: BHI 0.9 +/- 0.2 vs PI 0.6 +/- 0.1 micrograms/120 min; during IHT: BHI 12.6 +/- 2.2 vs PI 13.4 +/- 2.5 micrograms/120 min; after IHT: BHI 2.5 +/- 0.7 vs PI 3.7 +/- 1.3 micrograms/120 min). No differences in the minima of serum potassium levels were observed (BHI 3.38 +/- 0.04 vs PI 3.33 +/- 0.05 mmol/l). We conclude that the biological effects of human insulin and pork insulin are comparable. Our data do not support the assumption of a different hypothalamic handling of human insulin (recombinant DNA) and porcine insulin.