The Correlation Between Airway Inflammation and Loss of Deep Inhalation Bronchoprotection in Asthmatics

NCT00404677 | Completed

• 1 other identifier: BIO-REB 06-92
• Study Type: interventional
• Target: 18
• Locations: 0 countries
• Sites: N/A

Brief Summary

The loss of deep inhalation bronchoprotection in asthmatic individuals has been shown to be related to the degree of airway hyperresponsiveness, a hallmark of asthma. In several studies, asthmatic individuals with mild airway hyperresponsiveness (AHR) (methacholine PC20 \> 2 mg/mL) had a difference in methacholine PC20 with and without deep inhalations that averaged 1.8 doubling methacholine concentrations (p=0.0003). Conversely, asthmatic individuals with moderate to severe AHR (methacholine PC20 ≤ 2 mg/mL) had a non-significant difference in methacholine PC20 with and without deep inhalations (p=0.09). This loss of deep inhalation bronchoprotection is also now believed to play an important role in the pathogenesis of asthma. Airway inflammation is another of the key features of asthma and information on airway inflammation is increasingly being used in the diagnosis and treatment of asthma. The level of airway inflammation (as measured by fraction of exhaled nitric oxide and sputum eosinophilia) has also been shown to be correlated to the level of airway hyperresponsiveness (as measured by methacholine PC20). In addition, glucocorticoids have been shown to decrease airway hyperresponsiveness, further suggesting that these two phenomena, airway inflammation and airway hyperresponsiveness, are related. We therefore suggest that the degree of airway inflammation is related to the loss of deep inhalation bronchoprotection and expect there to be a negative correlation between the degree of deep inhalation bronchoprotection and airway inflammation.

Conditions

Asthma

Outcome Measures

Primary Outcomes (1)

• fraction of exhaled nitric oxide, sputum eosinophils and methacholine PC20

  freaction of exhaled nitric oxide data collected prior to methacholine challenges; sputum collected after the first methacholine challenge

Study Arms (2)

Standard

PLACEBO COMPARATOR

Methacholine challenges are performed using the standardized two minute tidal breathing method

Other: deep inhalation

Modified

ACTIVE COMPARATOR

Five deep inhalation maneouvers are incorporated into the standardized methacholine challenge

Other: deep inhalation

Interventions

deep inhalation OTHER

deep inhalation is comprised of an inhalation manoeuver from FRC to TLC

Modified; Standard

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• diagnosis of asthma

You may not qualify if:

• other lung disease(s)
• smoking

Sponsors & Collaborators

• University of Saskatchewan: lead

MeSH Terms

Conditions

Asthma

Condition Hierarchy (Ancestors)

Bronchial Diseases; Respiratory Tract Diseases; Lung Diseases, Obstructive; Lung Diseases; Respiratory Hypersensitivity; Hypersensitivity, Immediate; Hypersensitivity; Immune System Diseases

Study Officials

• Donald Cockcroft, MD, FRCP(C)

  Department of Medicine, Division of Respirology, Critical Care and Sleep Medicine, University of Saskatchewan

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER

Study Record Dates

• First Submitted: November 27, 2006
• First Posted: November 29, 2006
• Study Start: June 1, 2006
• Primary Completion: February 1, 2007
• Study Completion: February 1, 2007
• Last Updated: January 23, 2008

Record last verified: 2008-01