Assessment of adrenal suppression in children with asthma treated with inhaled corticosteroids: use of dehydroepiandrosterone sulfate as a screening test.

BACKGROUND: Inhaled corticosteroids (ICs) are considered first-line therapy for persistent asthma. At medium to high doses, ICs can suppress the hypothalamic-pituitary-adrenal (HPA) axis. Various provocative stimuli have been used to evaluate HPA axis function, but they are labor intensive and time-consuming. Dehydroepiandrosterone sulfate (DHEA-S) is a corticotropin-dependent adrenal androgen precursor that is suppressible in patients treated with ICs.
OBJECTIVES: To evaluate DHEA-S as a possible marker for HPA axis dysfunction in children treated with ICs.
METHODS: Children with moderate-to-severe persistent asthma and a history of medium- to high-dose IC exposure for at least 6 months were evaluated using low-dose and standard high-dose cosyntropin stimulation testing to assess adrenal function, and DHEA-S levels were compared with the results.
RESULTS: Thirteen (59%) of 22 patients exhibited an abnormal cortisol response to cosyntropin. Age- and sex-specific mean DHEA-S z scores were significantly lower in cosyntropin abnormal responders (-1.2822) compared with normal responders (0.2964) (P = .008). The receiver operating characteristic curve for DHEA-S z scores had an area of 0.786 (95% confidence interval, 0.584-0.989), reaching 100% sensitivity with a DHEA-S z score of -1.5966 or less and 100% specificity with a DHEA-S z score greater than 0.0225.
CONCLUSIONS: Most children develop biochemical evidence of adrenal suppression after treatment with medium to high doses of ICs. The presence of low DHEA-S levels can be used as a screening test to identify the child who needs more formal testing of the HPA axis.