Urinary excretion of adrenaline and noradrenaline during hypoglycaemic clamp in diabetic and non-diabetic adolescents

Abstract

The urinary excretion of non-conjugated adrenaline and noradrenaline during hypoglycaemic clamp was investigated in 16 diabetic and 15 non-diabetic adolescents. In the diabetic adolescents, the mean excretion of adrenaline was approximately nine times higher in clamp urine than in morning urine (p < 0.0001). In the non-diabetic adolescents, the mean excretion of adrenaline was 20-30 times higher in clamp urine than in morning urine (p < 0.0001). Plasma catecholamines were measured, and the area under the plasma concentration- time curve (AUC) and renal clearance of catecholamines were calculated. There was a linear correlation between the AUC and the urinary excretion of adrenaline (r=0.57, p= 0.001) and noradrenaline (r=0.49. p= 0.006) during the hypoglycaemic clamp. The renal clearance of adrenaline and noradrenaline did not differ between the diabetic and non-diabetic subjects. In the diabetic group, there was a positive correlation between HbA, and the adrenaline excretion in clamp urine (r =0.60, p = 0.015). The eight diabetic subjects with HbA_jc < 10% had lower adrenaline excretion in clamp urine than the subjects with HbA_jc > 10% and the non-diabetic subjects (all p values < 0.05). We conclude that there is a marked increase in urinary adrenaline excretion during hypoglycaemia in diabetic and non-diabetic adolescents. The increase in adrenaline excretion during hypoglycaemia was attenuated in the better-controlled diabetic adolescents in our study.

Key Words:

• catecholamines
• diabetes mellitus
• HPLC
• hormonal counterregulation
• hypoglycaemia
• metabolic control