Adrenaline and cortisol levels are lower during nighttime than daytime hypoglycaemia in children with type 1 diabetes.

AIM: We investigated children's counter regulatory hormone profiles during a hyperinsulinaemic hypoglycaemic clamp procedure at day and night.

METHODS: In 2013, we assessed the counter regulatory response to hypoglycaemia in eight outpatients with type 1 diabetes, recruited from the Herlev Hospital, Denmark, at a mean age of 9.6 ± 2.3 years. Hyperinsulinaemic 80 mU/m2 /min clamps were performed with a stepwise reduction in plasma glucose from euglycaemia (7-9 mmol/L) to hypoglycaemia (<3.5 mmol/L) and the glucose nadir (≤2.2 mmol/L) during the day and night. Adrenaline, cortisol, glucagon and growth hormone levels were assessed.

RESULTS: Adrenaline and growth hormone levels were higher during the day versus the night (p = 0.04 and p = 0.01, respectively). However, at the glucose nadir, the level of adrenaline was lower during the night than the day (0.6 ± 0.2 versus 1.9 ± 0.5 nmol/L, p = 0.016) and cortisol was lower during the day than the night (42 ± 15 versus 319 ± 81 nmol/L, p = 0.016). No differences were demonstrated for glucagon and growth hormone levels based on the same criteria.

CONCLUSION: The adrenaline response was blunted during nocturnal iatrogenic hypoglycaemia in our study cohort, and no increase in cortisol levels was demonstrated.