Frequency, severity and symptomatology of hypoglycaemia: a comparative trial of human and porcine insulins in type 1 diabetic patients.

A randomized, double-blind, cross-over trial was performed to compare the frequency, severity, and symptomatology of hypoglycaemia during treatment with porcine and human insulins. Forty patients with Type 1 diabetes (20 newly diagnosed and 20 with diabetes of 5-20 years duration) were treated with human and porcine insulins for consecutive 3-month periods, in random order. Episodes of hypoglycaemia were recorded prospectively with self-reporting of the presence and intensity of symptoms using a standardized scoring technique. Serial measurements of glycated haemoglobin and review of home blood glucose tests confirmed that similar glycaemic control was achieved with each insulin species. On comparison of the treatment periods with human and porcine insulins, no differences were demonstrated in the total frequency of symptomatic hypoglycaemia (3.10 vs 3.06 episodes patient-1 3-months-1; p = 0.94), the frequency of severe hypoglycaemia (0.1 vs 0.2 episodes patient-1 3-months-1; p = 0.44), the occurrence of asymptomatic biochemical hypoglycaemia (0.75 vs 0.68 episodes patient-1 3-months-1; p = 0.81), and the capillary blood glucose concentration at the onset of hypoglycaemic symptoms (2.6 +/- 0.2 vs 2.4 +/- 0.3 mmol l-1; p = 0.40), with all results being expressed for human vs porcine treatment periods, respectively. The symptoms of hypoglycaemia did not differ during the treatment periods with each insulin species. In conclusion, treatment with human insulin had no effect upon the symptomatic response to hypoglycaemia, did not increase the total frequency of hypoglycaemia, and did not emerge as a significant risk factor for severe hypoglycaemia in these patients.