Effect of Long-term Inhaled Corticosteroids on the Hypothalamic-Pituitary-Adrenal Axis in Children with Asthma

Objectives To assess the effect of the long-term use of inhaled corticosteroids (ICS) on the hypothalamic-pituitary-adrenal (HPA) axis. Methods Children (5–18 y) diagnosed with asthma and on ICS therapy for ≥6 mo were included. In the first step, screening with fasting at 8 AM, cortisol level was measured; a value <15 mcg/dl was considered low. Children with low fasting cortisol levels were subjected to adreno-corticotropic hormone (ACTH) stimulation test in the second step. Post-ACTH stimulation, cortisol level <18 mcg/dl was considered to have HPA axis suppression. Results A total of 78 children (males 55, 70.5%) diagnosed with asthma, with a median age of 11.5 (8, 14) y, were enrolled. The median duration of ICS use was 12 (12–24) mo. The median value of post-ACTH stimulation cortisol level was 22.5 (20.6, 25.5) mcg/dl, and a value <18 mcg/dl was observed in 4 (5.1%; 95% CI 0.2–10%) children. There was statistically no significant correlation between low post-ACTH stimulation cortisol level with ICS dose ( p = 0.23) and asthma control ( p = 0.67). None of the children had clinical features of adrenal insufficiency. Conclusions In this study, a few children had low post-ACTH stimulation cortisol values; however, none had clinical evidence of HPA axis suppression. Therefore, ICS is a safe drug in children for treating asthma, even for long-term use.