Hypothalamic-pituitary-adrenal axis suppression in asthmatic children on inhaled and nasal corticosteroids--more common than expected?

Abstract

Background: Hypothalamic pituitary adrenal axis suppression (HPAS) when treating asthmatic children with inhaled corticosteroids (ICS) is thought to be rare.

Objective: To determine the prevalence of HPAS in asthmatic children treated with ICS and nasal steroids (NS).

Methods: Twenty-six asthmatic children were recruited. Clinical features of HPAS, height, weight, height and weight velocity, steroid dose, adherence, symptom control and lung functions were documented. Metyrapone test was performed if the serum cortisol was > 83 nmol/L (> 3 microg/dL).

Results: No child had a serum cortisol < 83 nmol/L (< 3 microg/dL). Prevalence of HPAS was 35 (CI = 17%-56%). Daily NS dose/ m2 and cumulative NS dose/m2 were significantly (p = 0.03) inversely correlated with the post-metyrapone ACTH (r = -0.42 for both). Current ICS dose was not associated with the post-metyrapone ACTH (r = 0). There was a weak correlation with the daily ICS dose/m2 (r = -0.12) and cumulative ICS dose/m2 (r = -0.26).

Conclusions: A third of asthmatic children on ICS and NS develop HPAS. Contributing factors are the use of NS, body size and cumulative dose of ICS.