The effect of inhaled corticosteroids on hypothalamic-pituitary-adrenal axis

Abstract

Objectives:The aim of this study was to compare systemic effects of high-dose fluticasone propionate (FP) and beclomethasone dipropionate (BDP) via pressurized metered dose inhaler on adrenal and pulmonary function tests.Materials and Methods:A total of 66 patients with newly diagnosed moderate persistent asthma without previous use of asthma medications participated in this single blind, randomized, parallel design study. FP or BDP increased to 1 500 μg/d in 62 patients who had not received oral or IV corticosteroids in the previous six months. Possible effects of BDP and FP on adrenal function were evaluated by free cortisol level at baseline and after Synacthen test (250 μg). Fasting plasma glucose and pulmonary function tests were also assessed. Similar tests were repeated 3 weeks after increasing dose of inhaled corticosteroids to 1 500 μg/d.Results:No statistically significant suppression was found in geometric means of cortisol level post treatment in both groups. After treatment in FP group, mean forced expiratory volume in one second (FEV1) and mean forced vital capacity (FVC) values improved by 0.17 l (5.66% ± 13.91, P=0.031) and 0.18 l (5.09% ± 10.29, P=0.010), respectively. Although FEV1 and FVC improved in BDP group but was not statistically significant. Oral candidiasis and hoarseness were observed in 6.5% patients receiving BDP, but hoarseness was found in 3.2% patients in FP group (P=0.288).Conclusions:The results indicate that safety profiles of high doses of BDP and FP with respect to adrenal function are similar, but FP is more efficacious than that of BDP in improving pulmonary function test.

Systemic Effects of Inhaled Corticosteroids: An Overview

“…In addition most of the episodes include the use of fluticasone despite it being the least prescribed ICS in the patient population [ 14 , 15 ]. This is consistent with a meta-analysis showing that fluticasone was more effective in suppressing the adrenals vs budesonide [ 5 , 15 ]. The higher lipophilic properties and longer half-life [ 16 ] of fluticasone may explain this difference.…”

“…ICS have been found to affect the hypothalamo-pituitary-adrenal axis [ 4 ]. Exogenous corticosteroids act on the hypothalamus and anterior pituitary gland, and cause a negative feedback which attenuates the release of cortisol from the adrenal cortex [ 5 ]. This hypo-stimulation causes shrinkage of the adrenals due to disuse.…”

“…Several factors affect growth such as chronic disease, genetic background, suppression of the HPA axis and onset of puberty, and therefore it is difficult to fully assess the effects of steroids on growth [ 5 ]. Severe asthma therefore may confound the results of several studies which aim to determine whether ICS suppress growth.…”