Exhaled Nitric Oxide and Airway Caliber in Children With Asthma

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT01645397

Enrollment

Registered

2012-07-20

Start date

2011-06-30

Completion date

2013-08-31

Last updated

2014-01-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Asthma in Children

Keywords

Asthma, Deep inhalation, Exhaled nitric oxide

Brief summary

The purpose of this study is to assess if in steroid naïve asthmatic children with elevated baseline exhaled nitric oxide, treatment with inhaled steroid and normalization of exhaled nitric oxide level results in restoration of the bronchodilator response to deep inhalation.

Detailed description

Previous studies have shown that a deep inhalation (DI) would increase airway caliber in normal subjects. Whereas in asthmatics with spontaneous bronchoconstriction (obstruction of the airway), DI was shown to worsen airway obstruction. The mechanism for this variability in response to DI is not well-understood, but seems to be a key in understanding the pathophysiology of the disease, and possibly in the development of an effective therapy. Air way inflammation resulting in airway wall thickening and peribronchial edema is thought to play a role how the airway responds to deep inhalation. This study assess if reduction in airway inflammation (as measured by level of exhaled NO)results in optimization of the bronchodilator response to deep inhalation

Interventions

None listed

Study design

Observational model

COHORT

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

6 Years to No maximum

Healthy volunteers

Inclusion criteria

* Age: \> 6 years at age of screening. * Physician diagnosed asthma * Elevated exhaled NO at initial evaluation (\>25ppb) * Be able to reproducibly perform DI maneuvers and all other pulmonary function testing * Be clinically stable for at least 2 weeks prior to screening with no evidence of acute upper or lower respiratory infection or current pulmonary exacerbation. * Has not been on inhaled or oral steroid for at least 4 weeks prior to enrollment in the study. * Parent/child willingness to enroll in the study and provide written informed consent. * Be able to present for the required study visits.

Exclusion criteria

* Chest wall or spinal column deformity; known cardiac, neuromuscular, or other chronic diseases * Use of beta agonist, theophylline, leukotriene receptor antagonists, or caffeine-containing soft drinks 12 hr prior to the study. * Use of inhaled steroid in the past 4 weeks. * Respiratory infection or asthma exacerbation in the previous 2 weeks

Design outcomes

Primary

Measure	Time frame	Description
Change in M/P40 ratio from baseline at 4 weeks of treatment with inhaled steroid	at baseline and 4 weeks later	M/P40 ratio is defined as the ratio of flow at 40% of FVC (forced vital capacity) on the flow-volume curve after maximal inspiration to flow at 40% of FVC on the flow-volume curve after partial (60%-70% of FVC) inspiration (M/P40 ratio)

Secondary

Measure	Time frame	Description
Change in Ratio of post DI to pre DI airway resistance from baseline at 4 weeks of treatment with inhaled steroid	at baseline and 4 weeks later	Post-DI to pre-DI airway resistance at 5 Hz (R5) ratio (as measured by impulse oscillometry) from baseline (elevated exhaled NO) to 4-6 weeks of treatment.

Countries

United States

Outcome results