Abstract
BackgroundWhile most of the clinical benefits of inhaled corticosteroid (ICS) therapy may occur at low doses, results of dose-ranging studies are inconsistent. Although symptom/lung function response to low and high dose ICS medication is comparable, it is uncertain whether low dose ICSs are as effective as high dose in the treatment of inflammation and remodeling.Methods22 mild or moderate asthmatic adult subjects (corticosteroid free for > 2 months) participated in a randomized, parallel group study to compare effects of fluticasone propionate (FP) 200 mcg/day and 1000 mcg/day. Alveolar macrophage (AM)-derived cytokines and basement membrane thickness (BMT) were measured at baseline and after 7 weeks treatment while symptoms, spirometry, exhaled nitric oxide (eNO) and airway hyperresponsiveness (AHR) to mannitol at baseline and 6 weeks.ResultsFP improved spirometry, eNO, symptoms and AHR with no difference between low and high dose FP. Both high and low dose FP reduced GM-CSF, TNF-alpha and IL-1ra, with no change in BMT and with no differences between low and high dose FP.Conclusions200 μg/day of FP was as effective as 1000 μg/day in improving asthma control, airway inflammation, lung function and AHR in adults in the short term. Future studies should examine potential differential effects between low and high dose combination therapy (ICS/long acting beta agonist) on inflammation and airway remodeling over longer treatment periods.
Highlights
While most of the clinical benefits of inhaled corticosteroid (ICS) therapy may occur at low doses, results of dose-ranging studies are inconsistent
Paired clinical and in vitro data were available for 22 participants, of whom 11 had been randomized to low dose and 11 to high dose fluticasone propionate (FP)
In this study we found that seven weeks of low dose ICS treatment in adults with mild to moderate asthma, who were corticosteroid free for over 2 months, is as effective in controlling airway inflammation as high dose therapy, measured by constitutive mRNA expression of granulocyte macrophage-colony stimulating factor (GM-CSF), Tumour necrosis factor-alpha (TNF-a) and constitutive or LPS induced interleukin-1 receptor antagonist (IL-1ra) mRNA and protein in BAL
Summary
While most of the clinical benefits of inhaled corticosteroid (ICS) therapy may occur at low doses, results of dose-ranging studies are inconsistent. Symptom/lung function response to low and high dose ICS medication is comparable, it is uncertain whether low dose ICSs are as effective as high dose in the treatment of inflammation and remodeling. Many dose-ranging studies have been conducted to examine the dose-response relationship of ICSs in the treatment of asthma in adults and children [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17]. It has been suggested that most of the clinical benefits of ICSs occur at low doses [6,26], the results of dose-ranging studies are inconsistent. There are no in vivo randomized studies comparing the effects of low and high dose ICS on production of clinically relevant cytokines
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
