Corticosteroid Suppression in Patients Receiving Inhaled Glucocorticoids: Time to Reassess Risk?

Abstract

It is estimated that 350 million people worldwide are affected by asthma (1) and, as such, any associated complications of treatment have the potential for a significant impact on global public health. The recent study by Kachroo et al in Nature Medicine is a valuable addition to the literature in relation to adrenal suppression in patients receiving inhaled glucocorticoid (GC) therapy. The authors applied corticosteroid metabolomic profiling to address the question of adrenal suppression using several different large datasets and methodologies. They identified significant suppression in serum corticosteroids (and their precursors/metabolites) associated with adrenocorticotropin (ACTH)-dependent steroidogenesis in participants with asthma compared with controls and assessed the association with inhaled corticosteroid (ICS) exposure (2). Tertiary adrenal insufficiency (TAI) occurs due to suppression of the hypothalamic–pituitary–adrenal (HPA) axis by exogenous GC exposure and is reported in association with all GC preparations (3). As both oral and inhaled GC therapy form an important component of asthma management (1), patients with asthma are undoubtedly at risk of TAI. However, the prevalence and potential consequences of TAI in this cohort remain uncertain due to the many challenges in determining the full impact of GC exposure on adrenal function in asthma, which include the wide spectrum of cumulative GC exposure between patients, differences in potency between various ICS preparations, and the potential discrepancy between the prescribed ICS dose and the dose received by the patient because of suboptimal adherence to ICS medication and incorrect inhaler technique (4).