Symptoms of hypoglycemia — A comparison between porcine and human insulin

Summary

For more than 2 years now it has been controversially debated whether awareness of hypoglycemia is reduced when type I diabetic patients are switched from porcine to human insulin. In order to address this question, we studied nine C-peptide negative diabetics (age 27.6 years, Broca index 106%, duration of diabetes 5.7 years, HbA₁, 8.8%) in comparison with eight healthy volunteers (age 22.4 years, Broca index 104%). Following euglycemic monitoring overnight, a controlled hypoglycemia was induced by altering the algorithms of the Biostator. This was done in a double-blind, cross-over fashion using porcine or human insulin on 2 nonconsecutive days. There were no differences between the results obtained with respect to the time course of the study, blood glucose, amount of insulin infused, and concentration of venous free insulin achieved. Of the nine diabetics, eight were aware of hypoglycemia at a higher blood glucose level under porcine insulin. The first symptom of hypoglycemia was percieved at a mean blood glucose level of 61.1±5.4 mg/dl under porcine insulin and of 44.4 ± 5.3 mg/dl under human insulin (P≤0.05). Thirty symptoms were noted under porcine insulin exclusively or preferentially as opposed to only eight which were observed exclusively or preferentially under human insulin. The healthy volunteers evidenced fewer symptoms at lower blood glucose concentrations than the diabetics. The clear difference between human and porcine insulin could not unequivocally be reproduced in this group. We conclude that type I diabetic patients, who are maintained on a treatment regimen with human insulin, perceive symptoms of hypoglycemia at higher blood glucose concentrations when hypoglycemia is induced by porcine insulin as compared with human insulin. As every single patient and healthy volunteer was aware of at least one symptom of hypoglycemia under both insulins, it is possible to react appropriately to counteract this situation. Nevertheless, diabetic patients should be informed about this phenomenon.