Hypoglycaemia unawareness in diabetics transferred from beef/porcine insulin to human insulin.

The case-histories of 3 patients with insulin-dependent diabetes mellitus (IDDM) suggested that, after a switch from beef/porcine to human insulin, a given level of hypoglycaemia may cause less pronounced sympathoadrenal symptoms (tremor, sweating, &c), so that there is less warning of impending unconsciousness. This possibility was investigated by questioning of 176 IDDM patients who had switched from beef/porcine to human insulin with negligible change in dosage 1-48 months earlier. 66 (36%) said that their symptoms of hypoglycaemia had changed from those of sympathoadrenal activation to those of neuroglycopenia. This disadvantage of human insulin is an argument for continued availability of beef/porcine insulin.