Variability of methacholine bronchoprovocation and the effect of inhaled corticosteroids in mild asthma.

ABSTRACT:

Background

The methacholine challenge test quantifies airway hyper-responsiveness, which is measured by the provocative concentration of methacholine causing a 20% decrease in forced expiration volume in 1 second (PC20). The dose-response effect of inhaled corticosteroids (ICS) on PC20 has been inconsistent and within-patient variability of PC20 is not well established.

Objective

To determine the effect of high- vs low-dose ICS on PC20 and within-patient variability in those with repeated measurements of PC20.

Methods

A randomized, double-masked, crossover trial was conducted in patients with asthma on controller medications with PC20 of 8 mg/mL or lower (n = 64) to evaluate the effect of high-dose (1,000 μg/d) vs low-dose (250 μg/d) fluticasone for 4 weeks on PC20. I

SUBMITTER: Sumino K 

PROVIDER: S-EPMC3987862 | biostudies-literature | 2014 Apr

REPOSITORIES: biostudies-literature