Cortisol Responses to the Insulin Hypoglycaemia Test in Children

Horm Res. 2004;61(2):92-7. doi: 10.1159/000075339. Epub 2003 Dec 1.

Abstract

Aim: To determine the timing of the peak cortisol response to the insulin hypoglycaemia (IH) test in children and to establish paediatric reference data.

Methods: We retrospectively reviewed all IH tests in a tertiary paediatric endocrine referral centre over a 6-year period. Inclusion criteria were age <16 years and adequate hypoglycaemia (glucose < or =2.0 mmol/l). Patients with an impaired hypothalamic-pituitary-adrenal axis or receiving glucocorticoid medication were excluded. Fifty-four subjects (35 males) met the criteria. Blood samples were collected at -30, 0, 20, 30, 60, 90, 120, and 150 min in relation to insulin bolus injection (0.15 U/kg) at 0 min. Glucose, cortisol, and growth hormone (GH) were measured in all samples.

Results: Peak cortisol and GH responses occurred by 90 min in all subjects. Peak cortisol was inversely correlated with age (rs -0.65, p<0.0001). The median (5th centile) peak cortisol value was 689 nmol/l (547 nmol/l) in children younger than 10 years as compared with 555 nmol/l (468 nmol/l) in those older than 10 years (p<0.0001). Peak cortisol was not related to peak GH (rs -0.20, p=0.15).

Conclusions: Blood sampling in the IH test may be curtailed 90 min after injection. The peak cortisol response to IH is age related.

MeSH terms

  • Age Distribution
  • Child
  • Child, Preschool
  • Female
  • Human Growth Hormone / blood
  • Human Growth Hormone / metabolism*
  • Humans
  • Hydrocortisone / blood
  • Hydrocortisone / metabolism*
  • Hypoglycemia / blood*
  • Hypoglycemia / physiopathology
  • Infant
  • Insulin*
  • Male
  • Middle Aged
  • Patient Selection
  • Reference Values
  • Retrospective Studies

Substances

  • Insulin
  • Human Growth Hormone
  • Hydrocortisone