Different awareness of hypoglycaemia induced by human or purified pork insulin in type I diabetic patients

Abstract

Recently, there have been reports on a diminished awareness of hypoglycaemia after a switch from purified pork insulin (PPI) to human insulin (HI) in insulin-dependent diabetes mellitus (IDDM). To clarify this phenomenon we investigated nine IDDM patients without signs of autonomic neuropathy. After an overnight euglycaemic clamp, blood glucose was lowered to hypoglycaemic levels by means of an artificial pancreas (Biostator) on 2 days. Insulin was used in a double-blind, randomized, cross-over fashion, either PPI or HI. The symptomatology and the hormonal counterregulation of developing hypoglycaemia was recorded. Venous concentrations of free insulin, cortisol, glucagon, growth hormone and the prevailing blood glucose were similar under both insulins. Eight out of nine IDDM patiens felt more symptoms and at a higher blood glucose concentration under PPI than under HI. The first symptom of developing hypoglycaemia appeared at a mean blood glucose concentration of 61.1 ± 5.4 mg · dl −1 under PPI and 44.4 ± 5.3 mg · dl −1 under HI respectively ( P < 0.05). We conclude that HI may cause symptoms of hypoglycaemia to appear later and with a lesser number in comparison to PPI.