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

Abstract

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. We evaluated the function of the HPA axis in 58 ELBW infants receiving 9.0±7.2mg/kg of intravenous and 68.1±34.1mg/kg of oral hydrocortisone using a human corticotropin-releasing hormone stimulation test. The mean age at investigation was 12.0±5.2months. 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 >552nmol/L, or the increment was >193nmol/L than baseline concentration. 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 >386nmol/L without any episode of adrenal insufficiency. 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.