Counterregulatory hormone and symptom responses to hypoglycaemia in diabetic children

The hormonal responses to, and symptoms of, hypoglycaemia were investigated in 19 diabetic children (mean age 14.2 (SD 1.4) years, mean HbA1c 9.8 (SD 1.2)%) and 16 non-diabetic children (14.4(1.0) years) during a gradual reduction in plasma glucose with the glucose clamp technique. Plasma glucose was reduced from approximately 5.7 to approximately 2.6 mmol l(-1) in the diabetic children and from approximately 5.7 to approximately 2.9 mmol l(-1) in the non-diabetic children over 200 min. The mean glycaemic thresholds for adrenaline, and for autonomic and total symptom score, were similar in the diabetic and non-diabetic groups, and were found at plasma glucose levels between 3.4 and 3.7 mmol l(-1). The mean glucose levels which elicited increase of cortisol, growth hormone, and glucagon were lower (p < 0.01), and the mean incremental responses of adrenaline, cortisol, and glucagon were smaller in the diabetic than in the non-diabetic children. In the diabetic children, a correlation was found between Body Mass Index (BMI) and the hypoglycaemic thresholds for autonomic and total symptom scores (r = 0.64, p < 0.01 and r = 0.72, p = 0.001, respectively). We conclude that counterregulatory hormone responses are attenuated in diabetic as compared to non-diabetic children, whereas recognition of autonomic symptoms is similar in the two groups. Diabetic children with a higher BMI seem to have increased awareness of a declining plasma glucose level.