Low-dose adrenocorticotropic hormone stimulation testing in term infants

Area of Science:

• Pediatric Endocrinology
• Pediatric Endocrinology Research
• Adrenal Function Testing

Background:

• Low-dose adrenocorticotropic hormone (ACTH) stimulation testing is a standard method for evaluating adrenal function in children.
• Limited data exist on its use in term infants under 12 months outside the neonatal period.

Purpose of the Study:

• To assess the utility of the low-dose ACTH stimulation test in term infants younger than 12 months.
• To determine if a peak cortisol cutoff of 20 microg/dl is appropriate for evaluating adrenal function in this population.

Main Methods:

• Retrospective analysis of 14 term infants who underwent ACTH testing before 12 months of age.
• Evaluation of peak cortisol response to identify a suitable cutoff for distinguishing normal from abnormal adrenal function.

Main Results:

• Five infants with peak cortisol >= 20 microg/dl showed normal adrenal function.
• Nine infants with peak cortisol < 20 microg/dl on initial testing; four normalized upon repeat testing later in infancy.

Conclusions:

• The low-dose ACTH test effectively demonstrates normal adrenal function in term infants.
• The test has limited diagnostic value for secondary adrenal insufficiency (AI) in this age group.
• Clinical observation and repeat testing are crucial for diagnosing AI in infants with initial low cortisol responses.