Role of Counterregulatory Hormones for Glucose Metabolism in Children and Adolescents with Type 1 Diabetes

To elucidate the mechanism of insulin resistance due to insulin counterregulatory hormones (ICRHs) and evaluate ICRH secretion kinetics, ICRH concentrations were measured and correlated with blood glucose levels in 28 type 1 diabetic patients. Blood glucose was measured before bedtime. Early morning urine samples were collected the next morning before insulin injection and breakfast. Fasting blood glucose, cortisol, glucagon and HbA1c levels were measured. Growth hormone (GH), adrenaline, cortisol and C-peptide levels in morning urine samples were measured; SD scores were calculated for urine GH. The laboratory values (mean ± SD) were as follows; HbA1c of 8.1% ± 1.4%; pre-bedtime glucose of 203 ± 105 mg/dl; fasting blood glucose of 145 ± 87 mg/dl; serum cortisol of 21.6 ± 5.5 µg/dl; plasma glucagon of 98 ± 41 pg/ml; urinary GH, 27.2 ± 13.0 ng/gCr; urinary cortisol of 238 ± 197 ng/gCr; and urinary Adrenaline of 22.9 ± 21.0 ng/gCr. The mean urinary GH SD score was increased (+1.01 ± 0.70; p=0.000); the mean plasma glucagon lebel (98 ± 41 pg/ml) was not. Fasting blood glucose was positively correlated with plasma glucagon (R=0.378, p=0.0471) and negatively correlated with urinary cortisol (R=-0.476, p=0.010). Urinary adrenaline correlated positively with urinary GH (R=0.470, p=0.013) and urinary cortisol (R=0.522, p=0.004). In type 1 diabetes, GH, glucagon and cortisol hypersecretion may contribute to insulin resistance, but the mechanism remains unclear.