The prevalence of impaired glucose counter-regulation during an insulin-infusion test in insulin-treated diabetic patients prone to severe hypoglycaemia.

Among 603 patients over the age of 18, with insulin-treated diabetes mellitus, a questionnaire identified 98 patients who during a 12-month period had experienced severe hypoglycaemia, defined as an event which required the help of another person. Twenty of these patients had repeatedly suffered from such episodes, without any obvious reason, for a period of at least three years. The capacity to counter-regulate a standardized, insulin-infusion test (0.034 U.kg-1.h-1 given for 3 h unless severe neuroglucopenia developed) was evaluated in 14 of these patients. In 12, an impaired glucose counter-regulation was registered, defined as blood-glucose values below -2 SD of healthy subjects. In all but one of these patients, a combined deficiency of glucagon and adrenaline was documented, and was believed to be the likely cause of their inclination towards hypoglycaemia. In patients with severe hypoglycaemia, but not in diabetic patients without severe hypoglycaemia or in healthy subjects, a significant relationship between insulin disappearance and glucose rise was found. It is concluded that in insulin-treated diabetic patients, the prevalence of recurrent attacks of severe hypoglycaemia amounts to about 4%. In such patients, a combined deficiency of adrenaline and glucagon responses to hypoglycaemia is the predominant finding and the disappearance rate of insulin becomes critical for recovery of blood glucose after hypoglycaemia.