Counterregulatory hormonal response to insulin-induced hypoglycaemia in insulin-dependent diabetic patients: a comparison of equimolar amounts of porcine and semisynthetic human insulin.

Abstract

The aim of the present study was to compare the degree of hypoglycaemia, the hypoglycaemic symptom score and counterregulatory responses to equimolar amounts of intravenously administered porcine and semisynthetic human insulin in a double-blind crossover study in insulin-dependent diabetic patients. After overnight stabilization of blood glucose to approximately 6 mmol l-1, insulin was infused from 06.00 hours at such a rate as to keep the blood glucose concentration constant at 6 mmol l-1. At 09.00 hours hypoglycaemia was induced by increasing the infusion rate to give a blood glucose level of 2 mmol l-1 within about 60 min. The individual infusion rate from the first test was repeated in the second test, 1 week later. Blood glucose minimum levels were 2.1 (range, 1.3-2.9) and 2.1 (1.3-2.8) mmol l-1 for porcine and human insulin, respectively. The insulin concentrations at blood nadirs were 107 (66-180) and 107 (56-184) pmol l-1, respectively, for porcine compared to human insulin (NS). Symptom scores at minimum blood glucose concentrations were 43 and 46, respectively, with a maximal difference in intensity of 1 point in each patient. There were no statistical differences in the counterregulatory responses of glucagon, epinephrine, norepinephrine, cortisol, growth hormone, prolactin, beta-endorphine or in serum-potassium decreases. Patients were unable to discriminate between the two forms of insulin. It is concluded that there are no differences between porcine and semisynthetic insulin with regard to glucose fall, hormonal counterregulation or symptom scores, when the two forms of insulin are administered intravenously in equimolar amounts.