Background: There is evidence that baseline and peak cortisol response to the low dose short Synacthen test (LDSST) varies with pubertal status and gender in children with asthma on inhaled corticosteroids. There are no published data reporting effects of puberty on cortisol response to the insulin tolerance test (ITT) in childhood and adolescence.
Objective and hypotheses: To determine whether pubertal status, age or gender influence basal and peak cortisol concentrations to insulin induced hypoglycaemia in childhood and adolescence.
Method: The basal and peak cortisol concentrations in children and adolescents undergoing ITT for the investigation of short stature at a single centre were analysed retrospectively. The basal cortisol concentration was obtained at 0900 h after an overnight fast. Insulin, 0.15 units/kg (Actrapid) was administered i.v. to induce adequate hypoglycaemia and samples were collected at 20, 30, 45, 60, 90 and 120 min. Age, gender, Tanner pubertal stage, and peak cortisol were determined. The relationships between age, gender, pubertal status, basal and peak cortisol values were examined using ANOVA.
Results: 101 patients (79M, age 521 years) underwent an ITT. Forty eight patients (32M, range 721 years, median age 15 years) who were GH and cortisol sufficient (peak GH response≥6.4 μg/l and peak cortisol responses ≥500 nmol/l) were studied. The age, sex and puberty did not have a significant relationship to cortisol concentration. The cortisol concentrations in the pubertal and pre-pubertal groups are summarised in Table 1.
|Pre-pubertal (n=13)||Pubertal (n=35)||P value|
|Baseline cortisol (nmol/l)||221.31±73.075||278.89±117.53||0.107|
|Peak cortisol (nmol/l)||632.69±66.86||610.43±82.34||0.432|
Conclusion: Age, gender or pubertal status did not influence the baseline or peak cortisol responses to insulin induced hypoglycaemia. Caution is appropriate since pre-pubertal children are underrepresented in this study.
20 - 22 Sep 2014
European Society for Paediatric Endocrinology