Impaired counterregulatory hormone responses to hypoglycemia in children and adolescents with new onset IDDM.

Children with long-standing IDDM have impaired counterregulatory responses to hypoglycemia. To determine whether children with new onset IDDM also have altered counterregulation, we studied the counterregulatory responses to hypoglycemia in twenty children with new onset IDDM (5-6 days, age 12.6 +/- 2.9 yr, mean +/- SD), and compared these responses to 47 subjects with long-standing IDDM (duration 7.8 +/- 3.6 yr, age 15.3 +/- 2.5 yr) and 21 controls (age 14.2 +/- 2.8 yr). Six new onset subjects were restudied three months later during their remission. Glucose nadir in new onset (2.7 +/- 0.1 mmol.l-1) was similar to controls (2.4 +/- 0.1 mmol.l-1), but was higher than in long-standing IDDM (2.2 +/- 0.1 mmol.l-1). Both groups of diabetic subjects had lower glucagon responses to hypoglycemia than controls (p < 0.005). Glucagon responses in new and long-standing diabetes did not differ. Epinephrine was diminished in new IDDM compared to controls (p < 0.01). Glucose recovery was faster in new onset than in long-standing IDDM (p < 0.001) and the same as in controls. Responses remained diminished 3 months after diagnosis despite increased C-peptide and lower glycosylated hemoglobin. Thus, children with IDDM have diminished counterregulatory responses to hypoglycemia at diagnosis, that are similar to those in long-standing IDDM. The reasons for this impairment and its clinical application in childhood require further investigation.