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

Asthma Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00404677
• Other study ID #: BIO-REB 06-92
• Secondary ID: BIO-REB 06-92
• Status: Completed
• Phase: N/A
• First received: November 27, 2006
• Last updated: January 18, 2008
• Start date: June 2006
• Est. completion date: February 2007

Study information

• Verified date: January 2008
• Source: University of Saskatchewan
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Health Canada
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 18
• Est. completion date: February 2007
• Est. primary completion date: February 2007
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• diagnosis of asthma

Exclusion Criteria:

• other lung disease(s)

• smoking

Study Design

Allocation: Randomized, Intervention Model: Crossover Assignment, Masking: Open Label, Primary Purpose: Diagnostic

Related Conditions & MeSH terms

• Asthma

Intervention

Other:
• deep inhalation
deep inhalation is comprised of an inhalation manoeuver from FRC to TLC

Locations

Country	Name	City	State
n/a

Sponsors (1)

Lead Sponsor	Collaborator
University of Saskatchewan

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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	No