Hormonal counterregulation during severe hypoglycaemia under everyday conditions in patients with type 1 and insulin-treated type 2 diabetes mellitus

Aim: To determine the counterregulatory hormonal responses to severe hypoglycaemia (SH) in type 1 versus insulin-treated type 2 diabetic patients under everyday conditions. Methods: Counterregulatory hormones were determined in 28 consecutive type 1 and thirteen insulin-treated type 2 diabetic patients (age 54 +/- 18 vs. 75 +/- 13 yrs; diabetes duration 27 +/- 16 vs. 21 +/- 6 yrs) with SH requiring emergency treatment. Blood samples were taken prior to and after effective treatment of SH. SH was defined as an event with neuroglycopenic presentation requiring external intervention by administration of intravenous glucose or oral carbohydrates. 68% (19/28) of type 1 diabetic patients but none of those with type 2 diabetes had reduced awareness of hypoglycaemia. Results: Plasma glucose levels were 30 +/- 14 prior to and 179 +/- 82 mg/dl after treatment of SH; the time between the two measurements was 54 +/- 26 minutes. With the exception of higher levels of human growth hormone in type 1 patients - which were attributed to younger age - the other counterregulatory responses to SH showed no significant differences in type 1 vs. type 2 diabetic patients. In both groups glucagon responses were virtually absent while moderate catecholamine responses could be demonstrated. Treatment with beta-blockers did not affect hormonal counterregulation in type 1 diabetic patients. Conclusions: In patients approaching the insulin-deficient end of the spectrum of type 2 diabetes the hormonal responses to SH are comparable to those in patients with longstanding type 1 diabetes. Thus, in advanced type 2 diabetes the risk of developing SH may be similar to that in individuals with type 1 diabetes.