Neonatal hydrocortisone therapy does not have a serious suppressive effect on the later function of the hypothalamus-pituitary-adrenal axis.

AIM: This study investigated whether providing extremely low birthweight (ELBW) infants with a large amount of hydrocortisone had a serious suppressive effect on the later function of the hypothalamus-pituitary-adrenal (HPA) axis.

METHODS

We evaluated the function of the HPA axis in 58 ELBW infants receiving 9.0 ± 7.2 mg/kg of intravenous and 68.1 ± 34.1 mg/kg of oral hydrocortisone using a human corticotropin-releasing hormone stimulation test. The mean age at investigation was 12.0 ± 5.2 months. The response was judged to be normal when the maximum to minimum ratio of the plasma adrenocorticotropic hormone (ACTH) concentration was >2, the peak value of the serum cortisol concentration was >552 nmol/L, or the increment was >193 nmol/L than baseline concentration.

RESULTS

Of the 58 infants studied, 51 (88%) displayed a normal response to both the ACTH and cortisol secretion and seven infants (12%) who were judged to be poor responders exhibited a peak cortisol value of >386 nmol/L without any episode of adrenal insufficiency.

CONCLUSION

Providing ELBW infants with a daily low dose of long-term hydrocortisone therapy should not lead to a serious suppressive effect on the later function of the HPA axis, regardless of the administration method.