Symptomatic and counterregulatory hormonal responses to acute hypoglycaemia induced by insulin aspart and soluble human insulin in Type 1 diabetes

BACKGROUND: The aim of this study was to assess hypoglycaemia awareness with the insulin analogue, insulin aspart. The counterregulatory hormonal and symptomatic responses to hypoglycaemia induced by insulin aspart were compared with soluble human insulin in a double-blind, randomised, two-period crossover trial in patients with Type 1 diabetes. The primary objective was to compare the blood glucose threshold for autonomic activation during hypoglycaemia induced by insulin aspart and soluble human insulin. Secondary objectives were to compare the counterregulatory, symptomatic and physiological responses to hypoglycaemia. METHODS: 20 patients were screened, 17 were randomised and 16 completed the study. Acute hypoglycaemia was induced by intravenous infusion of insulin aspart or soluble human insulin (100 U ml(-1) at a rate of 2 mU kg(-1) min(-1)). RESULTS: No statistical difference between insulin aspart and soluble human insulin was shown for the primary blood glucose endpoint; mean arterialised blood glucose concentrations (+/-SD) at the onset of autonomic activation were 1. 88+/-0.39 mmol L(-1) for insulin aspart and 1.89+/-0.43 mmol L(-1) for soluble human insulin (not significant). No statistical differences were observed between the two insulins for the secondary endpoints: counterregulatory hormonal responses, autonomic responses, hypoglycaemia symptom scores, cognitive function and blood glucose responses. No serious adverse events were reported during the study. CONCLUSIONS: Insulin aspart and soluble human insulin elicit the same counterregulatory and symptomatic responses to acute hypoglycaemia in patients with Type 1 diabetes.