A comparison of the effects of human and animal insulin as well as of the adverse reaction profile did not show clinically relevant differences. Many patient-oriented outcomes like health-related quality of life or diabetes complications and mortality were never investigated in high-quality randomised clinical trials. The story of the introduction of human insulin might be repeated by contemporary launching campaigns to introduce pharmaceutical and technological innovations that are not backed up by sufficient proof of their advantages and safety.
Randomized trial of human versus animal species insulin in diabetic pregnant women: improved glycemic control, not fewer antibodies to insulin, influences birth weight.
Macrosomia occurs in infants of diabetic mothers in spite of "nearly normal maternal blood glucose levels" with insulin treatment. Insulin antibodies may carry bound insulin into the fetal blood and thus may be associated with fetal hyperinsulinemia and macrosomia in these infants. Our objective was to test the hypothesis that human insulin is associated with lower insulin antibody levels and less macrosomia than is animal species insulin.
                Forty-three insulin-requiring pregnant (< 20 weeks' gestation) women, previously treated with animal insulin, were randomized to human and animal insulins and studied at weeks 10 through 20, 24, 28, 32, 36, and 38, at delivery, and at 3 months post partum. Infant blood was drawn at delivery (cord) and at 1 day and 3 months post partum 1 hour after a glucose-amino acid challenge.
                Women receiving human insulin required significantly less insulin per kilogram of body weight and showed significant dampening of glucose excursions (p < 0.05 for each comparison). Infants born to mothers receiving human insulin weighed 2880 +/- 877 gm compared with 3340 +/- 598 gm for infants of women treated with animal insulin (p < 0.05). There was no difference in insulin antibody levels between groups for either mothers or infants. Infants born to mothers receiving human insulin had a 1 hour C-peptide level after the glucose-amino acid challenge at 3 months of age of 0.21 +/- 0.13 pmol/ml compared with 0.32 +/- 0.13 pmol/ml (p = 0.01).
                Administration of human insulin to pregnant diabetic women has a therapeutic advantage over animal insulin, with less maternal hyperglycemia or hypoglycemia, fewer larger-for-gestational-age infants, and less neonatal hyperinsulinemia. Our data do not support the hypothesis that maternal antibodies to insulin influence infant birth weight.